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Go

Go is played on a grid of black lines (usually19×19). Game pieces, called stones, are played on

the line intersections.

Years active Zhou Dynasty (1046–256 BC) topresent

Genre(s) Board gameAbstract strategy game

Players 2

Age range 3+[1][nb 1]

Setup time Minimal

Playing time Casual: 20–90 minutesTournament: 1–6 hours[a]

Randomchance

None

Skill(s)required

Strategy, tactics, observation

Synonym(s) Weiqi("way­chee")Igo / PadukBaduk

a Some professional games exceed 16 hours and are

played in sessions spread over two days.

Go (game)From Wikipedia, the free encyclopedia

"Goe" redirects here. For other uses, see GOE (disambiguation).This article is about weiqi. For other things named "Go", see Go (disambiguation).

Go (simplified Chinese: 围棋; traditional Chinese: 圍棋; pinyin: wéiqí, Japanese: 囲碁 igo,[nb 2] literalmeaning: "encircling game", Korean: 바둑baduk[nb 3]) is a board game involving two players,that originated in ancient China more than 2,500years ago. It was considered one of the four essentialarts of a cultured Chinese scholar in antiquity. Theearliest written reference to the game is generallyrecognized as the historical annal Zuo Zhuan[2][3] (c.4th century BC).[4]

There is significant strategy involved in the game,and the number of possible games is vast (10761

compared, for example, to the estimated 10120

possible in chess),[5] despite its relatively simplerules.

The two players alternately place black and whiteplaying pieces, called "stones", on the vacantintersections ("points") of a board with a 19x19 gridof lines. Beginners often play on smaller 9×9 and13×13 boards,[6] and archaeological evidence showsthat game was played in earlier centuries on a boardwith a 17×17 grid. By the time the game had spreadto Korea and Japan in about the 5th and 7th centuriesCE respectively, however, boards with a 19×19 gridhad become standard.[7]

The objective of the game—as the translation of itsname implies—is to have surrounded a larger totalarea of the board with one's stones than the opponentby the end of the game,[8] although this resulttypically involves many more intricacies than simplyusing surrounding areas directly.

Once placed on the board, stones may not be moved,but stones may be removed from the board ifcaptured—this is done by surrounding an opposingstone or group of stones by occupying allorthogonally­adjacent points.[9] The two playersplace stones alternately until they reach a point atwhich neither player wishes to make another move;the game has no set ending conditions beyond this.

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When a game concludes, the territory is counted along with captured stones and komi (points added tothe score of the player with the white stones as compensation for playing second) to determine thewinner.[10] Games may also be won by resignation.

As of mid­2008, there were well over 40 million Go players worldwide, the overwhelming majority ofthem living in East Asia.[11] As of May 2012, the International Go Federation has a total of 74 membercountries and four Association Members covering multiple countries.[12]

Contents

1 Overview1.1 Finer points

2 Game theory3 Rules

3.1 Basic rules3.2 The ko rule3.3 Suicide3.4 Komi3.5 Scoring rules3.6 Life and death3.7 Seki (mutual life)

4 Tactics4.1 Capturing tactics4.2 Reading ahead4.3 Ko fighting

5 Strategy5.1 Basic concepts5.2 Opening strategy5.3 Phases of the game

6 History6.1 Origin in China6.2 Spread to Korea and Japan6.3 Go in the West

7 Competitive play7.1 Ranks and ratings7.2 Tournament and match rules7.3 Top players and professional go

8 Equipment8.1 Traditional equipment

8.1.1 Boards8.1.2 Stones8.1.3 Bowls

8.2 Playing technique and etiquette8.3 Time control8.4 Notation and recording games

9 Computers and Go9.1 Nature of the game9.2 Software players9.3 Software assistance

10 In popular culture and science11 Psychology

12 Comparisons

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The first 60 moves of a Go gameanimated. This particular gamequickly developed into a complicatedfight in the lower left and bottom.(Click on the board, to restart theplay, in a larger window.)

12 Comparisons13 See also14 Notes15 References

15.1 Citations15.2 Bibliography

16 Further reading17 External links

Overview

Go is an adversarial game with the objective of havingsurrounded a larger total area of the board with one's stones thanthe opponent. As the game progresses, the players place stoneswhich map out formations and potential territories. Areas arecontested in battles between opposing stones, which are oftencomplex and may result in the expansion, reduction, or wholesalecapture and loss of the contested area.

A basic principle of Go is that stones must have at least one"liberty" (Chinese: 氣) to remain on the board. A "liberty" is anopen "point" (intersection) next to a stone. An enclosed liberty(or liberties) is called an "eye" (眼), and a group of stones with atleast two separate eyes is said to be unconditionally "alive".[14]

Such groups cannot be captured, even if surrounded.[15] "Dead"stones are stones that are surrounded and in groups with poorshape (one or no eyes), and thus cannot resist eventualcapture.[16]

The general strategy of Go is to expand one's territory wherepossible, attack the opponent's weak groups (groups that canpossibly be killed), and always stay mindful of the "life status" of one's own groups.[17][18] The libertiesof groups are countable. Situations where two opposing groups must capture the other to live are calledcapturing races ('semeai' [攻め合い] in Japanese).[19] In a capturing race, the group with more liberties(and/or better "shape") will ultimately be able to capture the opponent's stones.[19][20] Capturing racesand questions of life and death are examples of what makes Go challenging.

The game ends when both players pass, and players pass when there are no more profitable moves to bemade.[21] The game is then scored: The player with the greater number of controlled (surrounded) points,factoring in the number of captured stones and komi, wins the game.[22] Games may also be won byresignation, for example if a player has lost a large group of stones.

Finer points

In the opening stages of the game, players typically establish positions (or "bases") in the corners andaround the sides of the board. These bases help to quickly develop strong shapes which have manyoptions for life (self­viability for a group of stones which prevents capture and removal from the board)and establish formations for potential territory.[23] Players usually start in the corners, because it is more

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The four liberties (adjacent emptypoints) of a single black stone (A), asWhite reduces those liberties by one(B, C, and D). When Black has onlyone liberty left (D), that stone is "inatari".[13] White may capture thatstone (remove from board) with aplay on its last liberty (at D­1).

efficient to make life and to establish territory with the aid of twoedges of the board.[24] Established corner opening sequences arecalled "joseki" (Japanese, 定石) or "jungsuk" (in Korean) and areoften studied independently.[25]

"駄目" (pronounced [dame], 'neutral points') are points that lie in­between the boundary walls of black and white, and as such areconsidered to be of no value to either side. "Seki" (Chinese: 共活) are mutually alive pairs of white and black groups whereneither has two eyes. A "ko" (Chinese and Japanese: 劫) is arepeated­position shape that may be contested by making forcingmoves elsewhere. After the forcing move is played, the ko maybe "taken back" and returned to its original position.[26] Some"ko fights" may be important and decide the life of a large group,while others may be worth just one or two points. Some ko fightsare referred to as "picnic kos" when only one side has a lot tolose.[27] The Japanese call it a hanami (flower­viewing) ko.[28]

Playing with others usually requires a knowledge of each player'sstrength, as indicated by their rank(30kyu→1kyu|1dan→6dan|1dan pro→9dan pro). Handicaps canbe given if there is a difference in rank—Black is allowed toplace two or more stones on the board to compensate for White's greater strength.[29][30] There aredifferent rule­sets (Japanese, Chinese, AGA, etc.), which are almost entirely equivalent, except forcertain special­case positions.

Game theory

In formal game theory terms, Go is a non­chance, combinatorial game with perfect information.Informally that means there are no dice used (and decisions or moves create discrete outcome vectorsrather than probability distributions); the underlying math is combinatorial; and all moves (via singlevertex analysis) are visible to both players (unlike some card games where some information is hidden).Perfect information also implies sequence—players can theoretically know about all past moves.

Other game theoretical taxonomy elements include the facts that Go is bounded (because every gamemust end with a victor (or a tie) within a finite number of moves); the strategy is associative (everystrategy is a function of board position); format is non­cooperative (not a team sport); positions areextensible (can be represented by board position trees); game is zero­sum (player choices do not increaseresources available–colloquially, rewards in the game are fixed and if one player wins, the other loses)and the utility function is restricted (in the sense of win/lose; however, ratings, monetary rewards,national and personal pride and other factors can extend utility functions, but generally not to the extentof removing the win/lose restriction). Affine transformations are beyond the scope of this article, butthey can theoretically add non­zero and complex utility aspects even to two player games (see theMaschler reference on go/chess that follows here, p. 111).[31]

Rules

Main article: Rules of Go

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One black chain and two whitechains, with their liberties markedwith dots. Liberties are shared amongall stones of a chain and can becounted. Here the black group has 5liberties, while the two white chainshave 4 liberties each.

Aside from the order of play (alternating moves, Black moves first or takes a handicap) and scoringrules, there are essentially only two rules in Go:

Rule 1 (the rule of liberty) states that every stone remaining on the board must have at least oneopen "point" (an intersection, called a "liberty") directly next to it (up, down, left, or right), ormust be part of a connected group that has at least one such open point ("liberty") next to it.Stones or groups of stones which lose their last liberty are removed from the board.Rule 2 (the "ko rule") states that the stones on the board must never repeat a previous position ofstones. Moves which would do so are forbidden, and thus only moves elsewhere on the board arepermitted that turn.

Almost all other information about how the game is played is a heuristic, meaning it is learnedinformation about how the game is played, rather than a rule. Other rules are specialized, as they comeabout through different rule­sets, but the above two rules cover almost all of any played game.

Although there are some minor differences between rule sets used in different countries,[32] most notablyin Chinese and Japanese scoring rules,[33] these differences do not greatly affect the tactics and strategyof the game.

Except where noted otherwise, the basic rules presented here are valid independent of the scoring rulesused. The scoring rules are explained separately. Go terms for which there are no ready Englishequivalent are commonly called by their Japanese names.

Basic rules

Two players, Black and White, take turns placing a stone (gamepiece) of their own color on a vacant point (intersection) of thegrid on a Go board. Black moves first. If there is a largedifference in skill between the players, Black is typically allowedto place two or more stones on the board to compensate for thedifference (see Go handicaps). The official grid comprises 19×19lines, though the rules can be applied to any grid size. 13×13 and9×9 boards are popular choices to teach beginners.[34] Onceplaced, a stone may not be moved to a different point.[35]

Vertically and horizontally adjacent stones of the same colorform a chain (also called a string or group) that cannotsubsequently be subdivided and, in effect, becomes a singlelarger stone.[36] Only stones connected to one another by thelines on the board create a chain; stones that are diagonallyadjacent are not connected. Chains may be expanded by placingadditional stones on adjacent intersections, and can be connectedtogether by placing a stone on an intersection that is adjacent totwo or more chains of the same color.

A vacant point adjacent to a stone is called a liberty for that stone.[37][nb 4] Stones in a chain share theirliberties. A chain of stones must have at least one liberty to remain on the board. When a chain issurrounded by opposing stones so that it has no liberties, it is captured and removed from the board.

The ko rule

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If White plays at A, the black chainloses its last liberty. It is captured andremoved from the board. An example of a

situation in which theko rule applies

Under normal rules, White cannotplay at A because that point has noliberties. Under the Ing[40] and NewZealand rules,[41] White may play A(a ko threat), leaving an empty three­space eye. Black naturally answers byplaying at A, creating two eyes.

Players are not allowed to make a move that returns the game to the previous position. This rule, calledthe ko rule (Chinese: 劫; Japanese: 劫 kō "eon", Korean: 패; 'pae'), prevents unending repetition.[38] Asshown in the example pictured to the right: Black has just played the stone marked 1, capturing a whitestone at the intersection marked with a circle. If White were now allowed to play on the markedintersection, that move would capture the black stone marked 1 and recreate the situation before Blackmade the move marked 1. Allowing this could result in an unending cycle of captures by both players.

The ko rule therefore prohibits Whitefrom playing at the markedintersection immediately. InsteadWhite must play elsewhere, or pass;Black can then end the ko by filling atthe marked intersection, creating afive­stone black chain. If White wantsto continue the ko (that specificrepeating position), White tries to finda play elsewhere on the board thatBlack must answer; if Black answers,then White can retake the ko. A

repetition of such exchanges is called a ko fight.[39]

While the various rule­sets agree on the ko rule prohibiting returning the board to an immediatelyprevious position, they deal in different ways with the relatively uncommon situation in which a playermight recreate a past position that is further removed. See Rules of Go: Repetition for furtherinformation.

Suicide

A player may not place a stone such that it or its groupimmediately has no liberties, unless doing so immediatelydeprives an enemy group of its final liberty. In the latter case, theenemy group is captured, leaving the new stone with at least oneliberty.[42] This rule is responsible for the all­importantdifference between one and two eyes: if a group with only oneeye is fully surrounded on the outside, it can be killed with astone placed in its single eye.

The Ing and New Zealand rules do not have this rule,[43] andthere a player might destroy one of its own groups—"commitsuicide". This play would only be useful in a limited set ofsituations involving a small interior space.[44]

Komi

Main article: Komidashi

Because Black has the advantage of playing the first move, theidea of awarding White some compensation came into being during the 20th century. This is calledkomi, which gives white a 6.5 points compensation under Japanese rules (number of points varies byrule set).[45] If there is one stone (rank) difference in strength between players, the stronger player takes

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A simplified game at its end. Black'sterritory (A) is counted and comparedto White's territory (B). In thisexample, both Black and Whiteattempted to invade and live (C and Dgroups) to reduce the other's totalterritory. Only Black's invadinggroup (C) was successful in living, asWhite's group (D) was killed with ablack stone at E. The points in themiddle (F) are "dame", meaning theybelong to neither player.

white, and White may receive only 0.5 points komi, to break a possible tie ("jigo"). In handicap gameswith two or more handicap stones, White may also take 0.5 points komi to break a tie but it is morecommon that there is no komi.[46]

Scoring rules

Two general types of scoring system are used, and playersdetermine which to use before play. Both systems almost alwaysgive the same result. Territory scoring counts the number ofempty points a player's stones surround, together with thenumber of stones she or he captured. Area scoring counts thenumber of points your stones occupy and surround. It isassociated with contemporary Chinese play and was probablyestablished there during the Ming Dynasty in the 15th or 16thcentury.[47]

After both players have passed consecutively, the stones that arestill on the board but unable to avoid capture, called dead stones,are removed.

Area scoring (including Chinese): A player's score is thenumber of stones that the player has on the board, plus thenumber of empty intersections surrounded by that player's stones.

Territory scoring (including Japanese and Korean): In thecourse of the game, each player retains the stones they capture,termed prisoners. Any dead stones removed at the end of thegame become prisoners. The score is the number of empty pointsenclosed by a player's stones, plus the number of prisonerscaptured by that player.[nb 5]

If there is disagreement about which stones are dead, then underarea scoring rules, the players simply resume play to resolve the matter. The score is computed using theposition after the next time the players pass consecutively. Under territory scoring, the rules areconsiderably more complex; however, in practice, players generally play on, and, once the status of eachstone has been determined, return to the position at the time the first two consecutive passes occurredand remove the dead stones. For further information, see Rules of Go.

Given that the number of stones a player has on the board is directly related to the number of prisonerstheir opponent has taken, the resulting net score, that is the difference between Black's and White'sscores, is identical under both rulesets (unless the players have passed different numbers of times duringthe course of the game). Thus, the net result given by the two scoring systems rarely differs by morethan a point.[48]

Life and death

See also: Life and death

While not actually mentioned in the rules of Go (at least in simpler rule sets, such as those of NewZealand and the U.S.), the concept of a living group of stones is necessary for a practical understandingof the game.[49]

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Examples of eyes (marked).The black groups at the top ofthe board are alive, as theyhave at least two eyes. Theblack groups at the bottom aredead as they only have oneeye. The point marked a is afalse eye.

Example of seki (mutual life).Neither Black nor White can play onthe marked points without reducingtheir own liberties for those groups toone (self­atari).

When a group of stones is mostly surrounded and has no options toconnect with friendly stones elsewhere, the status of the group is eitheralive, dead or unsettled. A group of stones is said to be alive if itcannot be captured, even if the opponent is allowed to move first.Conversely, a group of stones is said to be dead if it cannot avoidcapture, even if the owner of the group is allowed the first move.Otherwise, the group is said to be unsettled: the defending player canmake it alive or the opponent can kill it, depending on who gets to playfirst.[49]

To be alive, a group must be able to create at least two "eyes" ifthreatened. An eye is an empty point that is surrounded by friendlystones, where the opponent can never play due to the suicide rule. Iftwo such eyes exist, the opponent can never capture a group of stones,because it always has at least two liberties. One eye is not enough forlife, because a point that would normally be suicide may be playedupon if doing so fills the last liberty of opposing stones, therebycapturing those stones. In the "Examples of eyes" diagram, all thecircled points are eyes. The two black groups in the upper corners arealive, as both have at least two eyes. The groups in the lower cornersare dead, as both have only one eye. The group in the lower left may

seem to have two eyes, but the surrounded empty point marked a is not actually an eye. White can playthere and take a black stone. Such a point is often called a false eye.[49]

Seki (mutual life)

There is an exception to the requirement that a group must havetwo eyes to be alive, a situation called seki (or mutual life).Where different colored groups are adjacent and share liberties,the situation may reach a position when neither player wants tomove first, because doing so would allow the opponent tocapture; in such situations therefore both player's stones remainon the board in mutual life or "seki". Neither player receives anypoints for those groups, but at least those groups themselvesremain living, as opposed to being captured.[nb 6]

Seki can occur in many ways. The simplest are: (1) each playerhas a group without eyes and they share two liberties, and (2)each player has a group with one eye and they share one moreliberty. In the "Example of seki (mutual life)" diagram, thecircled points are liberties shared by both a black and a whitegroup. Neither player wants to play on a circled point, becausedoing so would allow the opponent to capture. All the other groups in this example, both black andwhite, are alive with at least two eyes. Seki can result from an attempt by one player to invade and kill anearly settled group of the other player.[49]

Tactics

Main article: Go strategy and tactics

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A ladder. Black cannot escapeunless the ladder connects toblack stones further down theboard that will intercept withthe ladder.

A net. The chain of threemarked black stones cannotescape in any direction.

In Go, tactics deal with immediate fighting between stones, capturing and saving stones, life, death andother issues localized to a specific part of the board. Larger issues, not limited to only part of the board,are referred to as strategy, and are covered in their own section.

Capturing tactics

There are several tactical constructs aimed at capturing stones.[50] These are among the first things aplayer learns after understanding the rules. Recognizing the possibility that stones can be captured usingthese techniques is an important step forward.

The most basic technique is the ladder.[51] To capture stones in aladder, a player uses a constant series of capture threats—called atari—to force the opponent into a zigzag pattern as shown in the diagramto the right. Unless the pattern runs into friendly stones along the way,the stones in the ladder cannot avoid capture. Experienced playersrecognize the futility of continuing the pattern and play elsewhere. Thepresence of a ladder on the board does give a player the option to playa stone in the path of the ladder, thereby threatening to rescue theirstones, forcing a response. Such a move is called a ladder breaker andmay be a powerful strategic move. In the diagram, Black has the optionof playing a ladder breaker.

Another technique to capture stonesis the so­called net,[52] also known byits Japanese name, geta. This refers toa move that loosely surrounds somestones, preventing their escape in alldirections. An example is given in the diagram to the left. It isgenerally better to capture stones in a net than in a ladder, because anet does not depend on the condition that there are no opposing stonesin the way, nor does it allow the opponent to play a strategic ladderbreaker.

A third technique to capture stones is the snapback.[53] In a snapback,one player allows a single stone to be captured, then immediately playson the point formerly occupied by that stone; by so doing, the playercaptures a larger group of their opponent's stones, in effect snappingback at those stones. An example can be seen on the right. As with the

ladder, an experienced player does not play out such a sequence, recognizing the futility of capturingonly to be captured back immediately.

Reading ahead

One of the most important skills required for strong tactical play is the ability to read ahead.[54] Readingahead includes considering available moves to play, the possible responses to each move, and thesubsequent possibilities after each of those responses. Some of the strongest players of the game canread up to 40 moves ahead even in complicated positions.[55]

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A snapback. Although Blackcan capture the white stone byplaying at the circled point, theresulting shape for Black hasonly one liberty (at 1), thusWhite can then capture thethree black stones by playing at1 again (snap back).

A simplified ko fight on a 9×9 board.The ko is at the point marked with asquare—Black has "taken the ko"first. The ko fight determines the lifeof the A and B groups—only onesurvives and the other is captured.White may play C as a ko threat, andBlack properly answers at D. Whitecan then "take the ko" by playing atthe square­marked point (capturingthe one black stone). E is a possibleko threat for Black.

As explained in the scoring rules, some stone formations can never becaptured and are said to be alive, while other stones may be in theposition where they cannot avoid being captured and are said to bedead. Much of the practice material available to players of the gamecomes in the form of life and death problems, also known astsumego.[56] In such problems, players are challenged to find the vitalmove sequence that kills a group of the opponent or saves a group oftheir own. Tsumego are considered an excellent way to train a player'sability at reading ahead,[56] and are available for all skill levels, someposing a challenge even to top players.

Ko fighting

In situations when the Ko rule applies, a ko fight may occur.[39] If theplayer who is prohibited from capture is of the opinion that the captureis important, because it prevents a large group of stones from beingcaptured for instance, the player may play a ko threat.[39] This is amove elsewhere on the board that threatens to make a large profit if theopponent does not respond. If the opponent does respond to theko threat, the situation on the board has changed, and theprohibition on capturing the ko no longer applies. Thus theplayer who made the ko threat may now recapture the ko. Theiropponent is then in the same situation and can either play a kothreat as well, or concede the ko by simply playing elsewhere. Ifa player concedes the ko, either because they do not think itimportant or because there are no moves left that could functionas a ko threat, they have lost the ko, and their opponent mayconnect the ko.

Instead of responding to a ko threat, a player may also choose toignore the threat and connect the ko.[39] They thereby win the ko,but at a cost. The choice of when to respond to a threat and whento ignore it is a subtle one, which requires a player to considermany factors, including how much is gained by connecting, howmuch is lost by not responding, how many possible ko threatsboth players have remaining, what the optimal order of playingthem is, and what the size—points lost or gained—of each of theremaining threats is.[57]

Frequently, the winner of the ko fight does not connect the ko butinstead captures one of the chains that constituted theiropponent's side of the ko.[39] In some cases, this leads to anotherko fight at a neighboring location.

Strategy

Main article: Go strategy and tactics

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Strategy deals with global influence, interaction between distant stones, keeping the whole board inmind during local fights, and other issues that involve the overall game. It is therefore possible to allow atactical loss when it confers a strategic advantage.

Novices often start by randomly placing stones on the board, as if it were a game of chance. Anunderstanding of how stones connect for greater power develops, and then a few basic common openingsequences may be understood. Learning the ways of life and death helps in a fundamental way todevelop one's strategic understanding of weak groups.[nb 7] A player who both plays aggressively andcan handle adversity is said to display kiai, or fighting spirit, in the game.

Basic concepts

Main article: Go terms

Basic strategic aspects include the following:

Connection: Keeping one's own stones connected means that fewer groups need to make livingshape, and one has fewer groups to defend.Cut: Keeping opposing stones disconnected means that the opponent needs to defend and makeliving shape for more groups.Stay alive: The simplest way to stay alive is to establish a foothold in the corner or along one ofthe sides. At a minimum, a group must have two eyes (separate open points) to be "alive".[58] Anopponent cannot fill in either eye, as any such move is suicidal and prohibited in the rules.Mutual life (seki) is better than dying: A situation in which neither player can play on a particularpoint without then allowing the other player to play at another point to capture. The most commonexample is that of adjacent groups that share their last few liberties—if either player plays in theshared liberties, they can reduce their own group to a single liberty (putting themselves in atari),allowing their opponent to capture it on the next move.Death: A group that lacks living shape is eventually removed from the board as captured.Invasion: Set up a new living group inside an area where the opponent has greater influence,means one reduces the opponents score in proportion to the area one occupies.Reduction: Placing a stone far enough into the opponent's area of influence to reduce the amountof territory they eventually get, but not so far in that it can be cut off from friendly stones outside.Sente: A play that forces one's opponent to respond (gote). A player who can regularly play sentehas the initiative and can control the flow of the game.Sacrifice: Allowing a group to die in order to carry out a play, or plan, in a more important area.

The strategy involved can become very abstract and complex. High­level players spend years improvingtheir understanding of strategy, and a novice may play many hundreds of games against opponentsbefore being able to win regularly.

Opening strategy

In the opening of the game, players usually play in the corners of the board first, as the presence of twoedges makes it easier for them to surround territory and establish their stones.[59] After the corners, focusmoves to the sides, where there is still one edge to support a player's stones. Opening moves aregenerally on the third and fourth line from the edge, with occasional moves on the second and fifth lines.In general, stones on the third line offer stability and are good defensive moves, whereas stones on thefourth line influence more of the board and are good attacking moves. The opening is the most difficultpart of the game for professional players and takes a disproportionate amount of the playing time.[60]

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GoChinese name

Traditional Chinese圍棋

Simplified Chinese 围棋Literal meaning surround game

Transcriptions

Standard Mandarin

Hanyu Pinyin Wéiqí

Wade–Giles Wei­ch'i

Xiao'erjing

Tibetan name

Tibetan མག་མངས

In the opening, players often play established sequences called joseki, which are locally balancedexchanges;[61] however, the joseki chosen should also produce a satisfactory result on a global scale. It isgenerally advisable to keep a balance between territory and influence. Which of these gets precedence isoften a matter of individual taste.

Phases of the game

In the opening of the game, players usually play and gain territory in the corners of the board first, as thepresence of two edges make it easier for them to surround territory and establish their stones.[62] From asecure position in a corner, it is possible to lay claim to more territory by extending along the side of theboard.[63] The opening is the most theoretically difficult part of the game, and takes a large proportion ofprofessional players' thinking time.[62]

The middle phase of the game is the most combative, and usually lasts for more than 100 moves. Duringthe middlegame, the players invade each other's territories, and attack formations that lack the necessarytwo eyes for viability. Such groups may be saved or sacrificed for something more significant on theboard.[64] It is possible that one player may succeed in capturing a large weak group of the opponent's,which often proves decisive and ends the game by a resignation. However, matters may be morecomplex yet, with major trade­offs, apparently dead groups reviving, and skillful play to attack in such away as to construct territories rather than kill.[65]

The end of the middlegame and transition to the endgame is marked by a few features. The game breaksup into areas that do not affect each other (with a caveat about ko fights), where before the central areaof the board related to all parts of it. No large weak groups are still in serious danger. Moves canreasonably be attributed some definite value, such as 20 points or fewer, rather than simply beingnecessary to compete. Both players set limited objectives in their plans, in making or destroyingterritory, capturing or saving stones. These changing aspects of the game usually occur at much the sametime, for strong players. In brief, the middlegame switches into the endgame when the concepts ofstrategy and influence need reassessment in terms of concrete final results on the board.

History

Main article: History of Go

Origin in China

The earliest written reference to the game is generallyrecognized as the historical annal Zuo Zhuan[2][3] (c.4th century BC),[4] referring to a historical event of548 BC. It is also mentioned in Book XVII of theAnalects of Confucius[4] and in two books written byMencius[3][66] (c. 3rd century BC).[4] In all of theseworks, the game is referred to as yì (弈). Today, inChina, it is known as weiqi (simplified Chinese: 围棋;traditional Chinese: 圍棋; pinyin: wéiqí; Wade–Giles:wei ch'i), literally the "encirclement board game".

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Transcriptions

Wylie mig mangs

Korean name

Hangul 바둑

Transcriptions

Revised Romanization Baduk

McCune–Reischauer Paduk

Japanese name

Kanji 碁, 囲碁 ("surroundgame")

Transcriptions

Romanization Go, Igo

Woman Playing Go (TangDynasty c. 744), discoveredat the Astana Graves

Korean couple, in traditional dress,play in a photograph dated between1910 and 1920.

Illustrated handscrollof The Tale of Genji(12th century).

Go was originallyplayed on a 17×17 linegrid, but a 19×19 gridbecame standard bythe time of the TangDynasty (618–907).[3]Legends trace theorigin of the game tothe mythical Chineseemperor Yao (2337–2258 BC), who wassaid to have had hiscounselor Shun designit for his unruly son,Danzhu, to favorablyinfluence him.[67]Other theories suggest

that the game was derived from Chinese tribalwarlords and generals, who used pieces of stone tomap out attacking positions.[68][69]

In China, Go was considered one of the four cultivated arts of the Chinese scholar gentleman, along withcalligraphy, painting and playing the musical instrument guqin.[70]

Spread to Korea and Japan

Weiqi was introduced to Korea sometime between the 5th and 7th centuries CE, and was popular amongthe higher classes. In Korea, the game is called baduk (hangul: 바둑), and a variant of the game calledSunjang baduk was developed by the 16th century. Sunjang baduk became the main variant played inKorea until the end of the 19th century.[71][72]

The game reached Japan in the 7thcentury CE—where it is called go (碁)or igo (囲碁)—the game becamepopular at the Japanese imperial courtin the 8th century,[73] and among thegeneral public by the 13th century.[74]In 1603, Tokugawa Ieyasu re­established Japan's unified nationalgovernment. In the same year, heassigned the then­best player in Japan,a Buddhist monk named Nikkai (néKanō Yosaburo, 1559), to the post ofGodokoro (Minister of Go).[75] Nikkai

took the name Honinbo Sansa and founded the Honinbo Go school.[75] Severalcompeting schools were founded soon after.[75] These officially recognizedand subsidized Go schools greatly developed the level of play and introduced the dan/kyu style systemof ranking players.[76] Players from the four schools (Honinbo, Yasui, Inoue and Hayashi) competed inthe annual castle games, played in the presence of the shogun.[77]

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Go in the West

Despite its widespread popularity in East Asia, Go has been slow to spread to the rest of the world.Although there are some mentions of the game in western literature from the 16th century forward, Godid not start to become popular in the West until the end of the 19th century, when German scientistOskar Korschelt wrote a treatise on the game.[78] By the early 20th century, Go had spread throughoutthe German and Austro­Hungarian empires. In 1905, Edward Lasker learned the game while in Berlin.When he moved to New York, Lasker founded the New York Go Club together with (amongst others)Arthur Smith, who had learned of the game while touring the East and had published the book TheGame of Go in 1908.[79] Lasker's book Go and Go­moku (1934) helped spread the game throughout theU.S.,[79] and in 1935, the American Go Association was formed. Two years later, in 1937, the GermanGo Association was founded.

World War II put a stop to most Go activity, but after the war, Go continued to spread.[80] For most ofthe 20th century, the Japan Go Association (Nihon Ki­in) played a leading role in spreading Go outsideEast Asia by publishing the English­language magazine Go Review in the 1960s; establishing Go centersin the U.S., Europe and South America; and often sending professional teachers on tour to Westernnations.[81] Internationally, the game is now commonly known by its shortened Japanese name, andterms for common Go concepts are derived from their Japanese pronunciation.

In 1996, NASA astronaut Daniel Barry and Japanese astronaut Koichi Wakata became the first people toplay Go in space. They used a special Go set, which was named Go Space, designed by Wai­CheungWillson Chow.[82] Both astronauts were awarded honorary dan ranks by the Nihon Ki­in.[82]

As of May 2012, the International Go Federation has 57 member countries outside Asia.[12]

Competitive play

Ranks and ratings

Main article: Go ranks and ratings

In Go, rank indicates a player's skill in the game. Traditionally, ranks are measured using kyu and dangrades,[83] a system also adopted by many martial arts. More recently, mathematical rating systemssimilar to the Elo rating system have been introduced.[84] Such rating systems often provide amechanism for converting a rating to a kyu or dan grade.[84] Kyu grades (abbreviated k) are consideredstudent grades and decrease as playing level increases, meaning 1st kyu is the strongest available kyugrade. Dan grades (abbreviated d) are considered master grades, and increase from 1st dan to 7th dan.First dan equals a black belt in eastern martial arts using this system. The difference among eachamateur rank is one handicap stone. For example, if a 5k plays a game with a 1k, the 5k would need ahandicap of four stones to even the odds. Top­level amateur players sometimes defeat professionals intournament play.[85] Professional players have professional dan ranks (abbreviated p). These ranks areseparate from amateur ranks.

The rank system comprises, from the lowest to highest ranks:

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Three Japanese professional Goplayers observe some youngeramateurs as they dissect a life anddeath problem in the corner of theboard, at the US Go Congress inHouston, Texas, 2003.

Rank Type Range StageDouble­digit kyu 30–21k BeginnerDouble­digit kyu 20–10k Casual playerSingle­digit kyu 9–1k Intermediate/club playerAmateur dan 1–7d (where 8d is a special title) Advanced playerProfessional dan 1–9p (where 10p is a special title) Professionals

Tournament and match rules

See also: Go competitions

Tournament and match rules deal with factors that may influence the game but are not part of the actualrules of play. Such rules may differ between events. Rules that influence the game include: the setting ofcompensation points (komi), handicap, and time control parameters. Rules that do not generallyinfluence the game are: the tournament system, pairing strategies, and placement criteria.

Common tournament systems used in Go include the McMahon system,[86] Swiss system, leaguesystems and the knockout system. Tournaments may combine multiple systems; many professional Gotournaments use a combination of the league and knockout systems.[87]

Tournament rules may also set the following:

compensation points, called komi, which compensate the second player for the first moveadvantage of his opponent; tournaments commonly use a compensation in the range of 5–8points,[88] generally including a half­point to prevent draws;handicap stones placed on the board before alternate play, allowing players of different strengths

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Honinbo Shusai (left), last head ofhouse Honinbo, plays against then­up­and­coming Go Seigen in thegame of the century.

to play competitively (see Go handicap for more information); andsuperko: Although the basic ko rule described above covers more than 95% of all cycles occurringin games,[89] there are some complex situations—triple ko, eternal life,[nb 8] etc.—that are notcovered by it but would allow the game to cycle indefinitely. To prevent this, the ko rule issometimes extended to disallow the repetition of any previous position. This extension is calledsuperko.[89]

Top players and professional go

See also: Go players, Go professional and List of professional Go tournaments

A Go professional is a professional player of the game of Go. There are six areas with professional goassociations, these are: China (China Qiyuan), Japan (Nihon Ki­in, Kansai Ki­in), Korea (Korea BadukAssociation), Taiwan (Taiwan Chi Yuan Culture Foundation), the United States (AGA ProfessionalSystem) and Europe (European Professional System).

Although the game was developed in China, the establishment of the Four Go houses by TokugawaIeyasu at the start of the 17th century shifted the focus of the Go world to Japan. State sponsorship,allowing players to dedicate themselves full­time to study of the game, and fierce competition betweenindividual houses resulted in a significant increase in the level of play. During this period, the bestplayer of his generation was given the prestigious title Meijin (master) and the post of Godokoro(minister of Go). Of special note are the players who were dubbed Kisei (Go Sage). The only threeplayers to receive this honor were Dosaku, Jowa and Shusaku, all of the house Honinbo.[90]

After the end of the Tokugawa shogunate and the MeijiRestoration period, the Go houses slowly disappeared, and in1924, the Nihon Ki­in (Japanese Go Association) was formed.Top players from this period often played newspaper­sponsoredmatches of 2–10 games.[91] Of special note are the (Chinese­born) player Go Seigen (Chinese: Wu Qingyuan), who scored80% in these matches,[92] and Minoru Kitani, who dominatedmatches in the early 1930s.[93] These two players are alsorecognized for their groundbreaking work on new opening theory(Shinfuseki).[94]

For much of the 20th century, Go continued to be dominated byplayers trained in Japan. Notable names included Eio Sakata, Rin

Kaiho (born in China), Masao Kato, Koichi Kobayashi and Cho Chikun (born Cho Ch'i­hun, SouthKorea).[95] Top Chinese and Korean talents often moved to Japan, because the level of play there washigh and funding was more lavish. One of the first Korean players to do so was Cho Namchul, whostudied in the Kitani Dojo 1937–1944. After his return to Korea, the Hanguk Kiwon (Korea BadukAssociation) was formed and caused the level of play in South Korea to rise significantly in the secondhalf of the 20th century.[96] In China, the game declined during the Cultural Revolution (1966–1976) butquickly recovered in the last quarter of the 20th century, bringing Chinese players, such as Nie Weipingand Ma Xiaochun, on par with their Japanese and Korean counterparts.[97] The Chinese WeiqiAssociation (today part of the China Qiyuan) was established in 1962, professional dan grades startedbeing issued in 1982.[98] Western professional go began in 2012 with the American Go Association'sProfessional System.[99] In 2014, the European Go Federation followed suit and started theirprofessional system.[100]

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Korean player Lee Chang­ho,regarded by many as one of the bestmodern Go players, plays againstRussian player AlexandreDinerchtein, seven­time EuropeanChampion and one of the fewWestern players to reach professionalstatus.

With the advent of major international titles from 1989 onward,it became possible to compare the level of players from differentcountries more accurately. Korean players such as Lee Chang­ho,Cho Hunhyun, Lee Sedol and Yoo Changhyuk dominatedinternational Go and won many titles.[101] Several Chineseplayers also rose to the top in international Go, most notably MaXiaochun, Chang Hao and Gu Li. As of 2013, Japan lags behindin the international Go scene.

Historically, as with most sports and games, more men thanwomen have played Go. Special tournaments for women exist,but until recently, men and women did not compete together atthe highest levels; however, the creation of new, opentournaments and the rise of strong female players, most notablyRui Naiwei, have in recent years highlighted the strength andcompetitiveness of emerging female players.[102]

The level in other countries has traditionally been much lower,except for some players who had preparatory professionaltraining in Asia.[nb 9] Knowledge of the game has been scant elsewhere up until the 20th century. Afamous player of the 1920s was Edward Lasker.[nb 10] It was not until the 1950s that more than a fewWestern players took up the game as other than a passing interest. In 1978, Manfred Wimmer becamethe first Westerner to receive a professional player's certificate from an Asian professional Goassociation.[103] In 2000, a Westerner, Michael Redmond, finally achieved the top rank awarded by anAsian Go association, 9 dan. In total, as of 2008, only nine non­Asian Go players have ever achievedprofessional status in Asian associations.

Equipment

Main article: Go equipment

It is possible to play Go with a simple paper board and coins or plastic tokens for the stones. Morepopular midrange equipment includes cardstock, a laminated particle board, or wood boards with stonesof plastic or glass. More expensive traditional materials are still used by many players.The mostexpensive Go sets have black stones carved from slate and white stones carved from translucent whiteshells, played on boards carved in a single piece from the trunk of a tree.

Traditional equipment

Boards

The Go board (generally referred to by its Japanese name goban (碁盤)) typically measures between 45and 48 cm (18 and 19 in) in length (from one player's side to the other) and 42 to 44 cm (17 to 17 in) inwidth. Chinese boards are slightly larger, as a traditional Chinese Go stone is slightly larger to match.The board is not square; there is a 15:14 ratio in length to width, because with a perfectly square board,from the player's viewing angle the perspective creates a foreshortening of the board. The added lengthcompensates for this.[104] There are two main types of boards: a table board similar in most respects toother gameboards like that used for chess, and a floor board, which is its own free­standing table and atwhich the players sit.

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A traditional Japanese set, with asolid wooden floor board (碁盤

goban), 2 bowls (碁笥 goke) and 361stones (碁石 goishi)

The traditional Japanese goban is between 10 and 18 cm (3.9 and7.1 in) thick and has legs; it sits on the floor (see picture).[104] Itis preferably made from the rare golden­tinged Kaya tree(Torreya nucifera), with the very best made from Kaya trees upto 700 years old. More recently, the related California Torreya(Torreya californica) has been prized for its light color and palerings as well as its reduced expense and more readily availablestock. The natural resources of Japan have been unable to keepup with the enormous demand for the slow­growing Kaya trees;both T. nucifera and T. californica take many hundreds of yearsto grow to the necessary size, and they are now extremely rare,raising the price of such equipment tremendously.[105] As Kayatrees are a protected species in Japan, they cannot be harvesteduntil they have died. Thus, an old­growth, floor­standing Kayagoban can easily cost in excess of $10,000 with the highest­quality examples costing more than $60,000.[106]

Other, less expensive woods often used to make quality tableboards in both Chinese and Japanese dimensions include Hiba(Thujopsis dolabrata), Katsura (Cercidiphyllum japonicum),Kauri (Agathis), and Shin Kaya (various varieties of spruce,commonly from Alaska, Siberia and China's YunnanProvince).[105] So­called Shin Kaya is a potentially confusingmerchant's term: shin means "new", and thus shin kaya is best translated "faux kaya", because the woodsso described are biologically unrelated to Kaya.[105]

Stones

A full set of Go stones (goishi) usually contains 181 black stones and 180 white ones; a 19×19 grid has361 points, so there are enough stones to cover the board, and Black gets the extra odd stone becausethat player goes first.

Traditional Japanese stones are double­convex, and made of clamshell (white) and slate (black).[107] Theclassic slate is nachiguro stone mined in Wakayama Prefecture and the clamshell from the Hamaguriclam; however, due to a scarcity in the Japanese supply of this clam, the stones are most often made ofshells harvested from Mexico.[107] Historically, the most prized stones were made of jade, often given tothe reigning emperor as a gift.[107]

In China, the game is traditionally played with single­convex stones[107] made of a composite calledYunzi. The material comes from Yunnan Province and is made by sintering a proprietary and trade­secret mixture of mineral compounds derived from the local stone. This process dates to the TangDynasty and, after the knowledge was lost in the 1920s during the Chinese Civil War, was rediscoveredin the 1960s by the now state­run Yunzi company. The material is praised for its colors, its pleasingsound as compared to glass or to synthetics such as melamine, and its lower cost as opposed to othermaterials such as slate/shell. The term "yunzi" can also refer to a single­convex stone made of anymaterial; however, most English­language Go suppliers specify Yunzi as a material and single­convex asa shape to avoid confusion, as stones made of Yunzi are also available in double­convex while syntheticstones can be either shape.

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An example of single­convex stonesand Go Seigen bowls. Theseparticular stones are made of Yunzimaterial, and the bowls of jujubewood.

Go players in Shanghai demonstratethe traditional technique of holding astone.

Traditional stones are made so that black stones are slightly larger in diameter than white; this is tocompensate for the optical illusion created by contrasting colors that would make equal­sized whitestones appear larger on the board than black stones.[107][nb 11]

Bowls

The bowls for the stones are shaped like a flattened sphere with alevel underside.[108] The lid is loose fitting and upturned beforeplay to receive stones captured during the game. Chinese bowlsare slightly larger, and a little more rounded, a style knowngenerally as Go Seigen; Japanese Kitani bowls tend to have ashape closer to that of the bowl of a snifter glass, such as forbrandy. The bowls are usually made of turned wood. Mulberry isthe traditional material for Japanese bowls, but is very expensive;wood from the Chinese jujube date tree, which has a lighter color(it is often stained) and slightly more visible grain pattern, is acommon substitute for rosewood, and traditional for Go Seigen­style bowls. Other traditional materials used for making Chinesebowls include lacquered wood, ceramics, stone and woven straw

or rattan. The names of the bowl shapes, "Go Seigen" and "Kitani", were introduced in the last quarter ofthe 20th century by the professional player Janice Kim as homage to two 20th­century professional Goplayers by the same names, of Chinese and Japanese nationality, respectively, who are referred to as the"Fathers of modern Go".[90]

Playing technique and etiquette

The traditional way to place a Go stone is to first take one fromthe bowl, gripping it between the index and middle fingers, withthe middle finger on top, and then placing it directly on thedesired intersection.[109] One can also place a stone on the boardand then slide it into position under appropriate circumstances(where it does not move any other stones). It is consideredrespectful towards White for Black to place the first stone of thegame in the upper right­hand corner.[110] (Because of symmetry,this has no effect on the game's outcome.)

It is considered poor manners to run one's fingers through one'sbowl of unplayed stones, as the sound, however soothing to theplayer doing this, can be disturbing to one's opponent. Similarly,"clacking" a stone against another stone, the board, or the table or floor is also discouraged. However, itis permissible to emphasize select moves by striking the board more firmly than normal, thus producinga sharp clack.

Time control

See also: Time control and Byoyomi

A game of Go may be timed using a game clock. Formal time controls were introduced into theprofessional game during the 1920s and were controversial.[111] Adjournments and sealed moves beganto be regulated in the 1930s. Go tournaments use a number of different time control systems. All

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common systems envisage a single main period of time for each player for the game, but they vary onthe protocols for continuation (in overtime) after a player has finished that time allowance.[nb 12] Themost widely used time control system is the so­called byoyomi[nb 13] system. The top professional Gomatches have timekeepers so that the players do not have to press their own clocks.

Two widely used variants of the byoyomi system are:[112]

Standard byoyomi: After the main time is depleted, a player has a certain number of time periods(typically around thirty seconds). After each move, the number of full­time periods that the playertook (often zero) is subtracted. For example, if a player has three thirty­second time periods andtakes thirty or more (but less than sixty) seconds to make a move, they lose one time period. With60–89 seconds, they lose two time periods, and so on. If, however, they take less than thirtyseconds, the timer simply resets without subtracting any periods. Using up the last period meansthat the player has lost on time.Canadian byoyomi: After using all of their main time, a player must make a certain number ofmoves within a certain period of time, such as twenty moves within five minutes.[112][nb 14] If thetime period expires without the required number of stones having been played, then the player haslost on time.[nb 15]

Notation and recording games

See also: Kifu

Go games are recorded with a simple coordinate system. This is comparable to algebraic chess notation,except that Go stones do not move and thus require only one coordinate per turn. Coordinate systemsinclude purely numerical (4­4 point), hybrid (K3), and purely alphabetical.[113] The Smart Game Formatuses alphabetical coordinates internally, but most editors represent the board with hybrid coordinates asthis reduces confusion. The Japanese word kifu is sometimes used to refer to a game record.

In Unicode, Go stones are encoded in the block Miscellaneous Symbols:

U+2686 WHITE CIRCLE WITH DOT RIGHT (HTML ⚆)[114]

U+2687 WHITE CIRCLE WITH TWO DOTS (HTML ⚇)

U+2688 BLACK CIRCLE WITH DOT RIGHT (HTML ⚈)

U+2689 BLACK CIRCLE WITH TWO DOTS (HTML ⚉)

Computers and Go

Nature of the game

See also: Go and mathematics

In combinatorial game theory terms, Go is a zero­sum, perfect­information, partisan, deterministicstrategy game, putting it in the same class as chess, checkers (draughts) and Reversi (Othello); howeverit differs from these in its game play. Although the rules are simple, the practical strategy is extremelycomplex.

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A finished beginner's game on a13×13 board. Go software can reachstronger levels on a smaller boardsize.

The game emphasizes the importance of balance on multiple levels and has internal tensions. To securean area of the board, it is good to play moves close together; however, to cover the largest area, oneneeds to spread out, perhaps leaving weaknesses that can be exploited. Playing too low (close to theedge) secures insufficient territory and influence, yet playing too high (far from the edge) allows theopponent to invade.

It has been claimed that Go is the most complex game in the world due to its vast number of variationsin individual games.[115] Its large board and lack of restrictions allow great scope in strategy andexpression of players' individuality. Decisions in one part of the board may be influenced by anapparently unrelated situation in a distant part of the board. Plays made early in the game can shape thenature of conflict a hundred moves later.

The game complexity of Go is such that describing even elementary strategy fills many introductorybooks. In fact, numerical estimates show that the number of possible games of Go far exceeds thenumber of atoms in the observable universe.[nb 16]

Research of go endgame by John H. Conway led to the invention of the surreal numbers.[116] Go alsocontributed to development of combinatorial game theory (with Go Infinitesimals[117] being a specificexample of its use in Go).

Software players

Main article: Computer Go

Go poses a daunting challenge to computer programmers. The best Go programs only manage to reachamateur dan level.[118] On the small 9×9 board, the computer fares better, and some programs now win afraction of their 9×9 games against professional players. Many in the field of artificial intelligenceconsider Go to require more elements that mimic human thought than chess.[119]

The reasons why computer programs do not play Go at theprofessional dan level include:[120]

The number of spaces on the board is much larger (overfive times the number of spaces on a chess board—361 vs.64). On most turns there are many more possible moves inGo than in chess. Throughout most of the game, thenumber of legal moves stays at around 150–250 per turn,and rarely falls below 50 (in chess, the average number ofmoves is 37).[121] Because an exhaustive computerprogram for Go must calculate and compare every possiblelegal move in each ply (player turn), its ability to calculatethe best plays is sharply reduced when there are a largenumber of possible moves. Most computer gamealgorithms, such as those for chess, compute several movesin advance. Given an average of 200 available moves through most of the game, for a computer tocalculate its next move by exhaustively anticipating the next four moves of each possible play(two of its own and two of its opponent's), it would have to consider more than 320 billion(3.2 × 1011) possible combinations. To exhaustively calculate the next eight moves, would requirecomputing 512 quintillion (5.12 ×1020) possible combinations. As of March 2014, the mostpowerful supercomputer in the world, NUDT's "Tianhe­2", can sustain 33.86 petaflops.[122] At thisrate, even given an exceedingly low estimate of 10 operations required to assess the value of one

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A 9×9 game with graphical aids.Colors and markings showevaluations by the computer assistant.

play of a stone, Tianhe­2 would require 4 hours to assess all possible combinations of the nexteight moves in order to make a single play.The placement of a single stone in the initial phase can affect the play of the game a hundred ormore moves later. A computer would have to predict this influence, and it would be unworkable toattempt to exhaustively analyze the next hundred moves.In capture­based games (such as chess), a position can often be evaluated relatively easily, such asby calculating who has a material advantage or more active pieces.[nb 17] In Go, there is often noeasy way to evaluate a position.[123] However a 6­kyu human can evaluate a position at a glance,to see which player has more territory, and even beginners can estimate the score within 10 points,given time to count it. The number of stones on the board (material advantage) is only a weakindicator of the strength of a position, and a territorial advantage (more empty points surrounded)for one player might be compensated by the opponent's strong positions and influence all over theboard. Normally a 3­dan can easily judge most of these positions.

As an illustration, the greatest handicap normally given to a weaker opponent is 9 stones. It was not untilAugust 2008 that a computer won a game against a professional level player at this handicap. It was theMogo program, which scored this first victory in an exhibition game played during the US GoCongress.[124][125]

Software assistance

Main article: Go software

An abundance of software is available to support players of thegame. This includes programs that can be used to view or editgame records and diagrams, programs that allow the user tosearch for patterns in the games of strong players, and programsthat allow users to play against each other over the Internet.

Some web servers provide graphical aids like maps, to aidlearning during play. These graphical aids may suggest possiblenext moves, indicate areas of influence, highlight vital stonesunder attack and mark stones in atari or about to be captured.

There are several file formats used to store game records, themost popular of which is SGF, short for Smart Game Format.Programs used for editing game records allow the user to recordnot only the moves, but also variations, commentary and further information on the game.[nb 18]

Electronic databases can be used to study life and death situations, joseki, fuseki and games by aparticular player. Programs are available that give players pattern searching options, which allow playersto research positions by searching for high­level games in which similar situations occur. Such softwaregenerally lists common follow­up moves that have been played by professionals and gives statistics onwin/loss ratio in opening situations.

Internet­based Go servers allow access to competition with players all over the world, for real­time andturn­based games.[nb 19] Such servers also allow easy access to professional teaching, with both teachinggames and interactive game review being possible.[nb 20]

In popular culture and science

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Apart from technical literature and study material, Go and its strategies have been the subject of severalworks of fiction, such as The Master of Go by Nobel prize­winning author Yasunari Kawabata[nb 21] andThe Girl Who Played Go by Shan Sa. Other books have used Go as a theme or minor plot device. Forexample, the novel Shibumi by Trevanian centers around the game and uses Go metaphors,[126] and TheWay of Go: 8 Ancient Strategy Secrets for Success in Business and Life by Troy Anderson applies Gostrategy to business.[127] GO: An Asian Paradigm for Business Strategy[128] by Miura Yasuyuki, amanager with Japan Airlines,[129] uses Go to describe the thinking and behavior of business men.[130]

Of particular note is the manga (Japanese comic book) and anime series Hikaru no Go, released in Japanin 1998, which had a large impact in popularizing Go among young players, both in Japan and—astranslations were released—abroad.[131][132] Go Player is a similar animated series about young Goplayers that aired in China.

Similarly, Go has been used as a subject or plot device in film, such as π, A Beautiful Mind, Tron:Legacy, and The Go Master, a biopic of Go professional Go Seigen.[133][nb 22] 2013's Tôkyô ni kitabakari or Tokyo Newcomer portrays a Chinese foreigner Go player moving to Tokyo.[134] In King Hu'swuxia film The Valiant Ones, the characters are color­coded as Go stones (black or other dark shades forthe Chinese, white for the Japanese invaders), Go boards and stones are used by the characters to keeptrack of soldiers prior to battle, and the battles themselves are structured like a game of Go.[135]

The corporation and brand Atari was named after the Go term.[136]

Hedge fund manager Mark Spitznagel used weiqi as his main investing metaphor in his popularinvesting book The Dao of Capital.[137]

Psychology

A 2004 review of literature by Fernand Gobet, de Voogt & Retschitzki[138] shows that relatively littlescientific research has been carried out on the psychology of Go, compared with other traditional boardgames such as chess and Mancala. Computer Go research has shown that given the large search tree,knowledge and pattern recognition are more important in Go than in other strategy games, such aschess.[138] A study of the effects of age on Go­playing[139] has shown that mental decline is milder withstrong players than with weaker players. According to the review of Gobet and colleagues, the pattern ofbrain activity observed with techniques such as PET and fMRI does not show large differences betweenGo and chess. On the other hand, a study by Xiangchuan Chen et al.[140] showed greater activation in theright hemisphere among Go players than among chess players. There is some evidence to suggest acorrelation between playing board games and reduced risk of Alzheimer's disease and dementia.[141]

Comparisons

Go begins with an empty board. It is focused on building from the ground up (nothing to something)with multiple, simultaneous battles leading to a point­based win. Chess is tactical rather than strategic, asthe predetermined strategy is to kill one individual piece (the king). This comparison has also beenapplied to military and political history, with Scott Boorman's 1969 book The Protracted Gameexploring the strategy of the Communist Party of China in the Chinese Civil War through the lens ofGo.[142]

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A similar comparison has been drawn among Go, chess and backgammon, perhaps the three oldestgames that enjoy worldwide popularity.[143] Backgammon is a "man vs. fate" contest, with chanceplaying a strong role in determining the outcome. Chess, with rows of soldiers marching forward tocapture each other, embodies the conflict of "man vs. man". Because the handicap system tells Goplayers where they stand relative to other players, an honestly ranked player can expect to lose abouthalf of their games; therefore, Go can be seen as embodying the quest for self­improvement, "man vs.self".[143]

See also

Benson's algorithm – a method for determining the chains that are unconditionally aliveGo opening strategyGo proverbsGo variants and Games played with Go equipmentList of Go organizationsList of professional Go tournamentsRoyal Game of Ur – a backgammon­like dice boardgame played in Near East ca. 2500–100 BC,known from archaeology

Notes1. Children below a certain age may swallow or choke on stones.2. The full Japanese name igo is derived from its Chinese name weiqi, which roughly translates as "board game

of surrounding"; see Etymology Of Go (http://senseis.xmp.net/?EtymologyOfGo) at Sensei's Library for moreinformation. To differentiate the game Go from the common English verb to go, it is generally capitalized(Gao 2007) or, in events sponsored by the Ing Foundation, spelled goe.

3. The Korean word 'baduk' derives from the Middle Korean word 'Badok', the meaning of which iscontroversial; the more plausible etymologies include the suffix '­ok' added to 'Bad' creating the meaning 'flatand wide board', or the joining of 'Bad', meaning 'field', and 'Dok', meaning 'stone'. Less plausibleetymologies include a derivation of 'Badukdok', referring to the playing pieces of the game, or a derivationfrom Chinese 排子, meaning 'to arrange pieces'.See 조, 항범 (October 8, 2005). 그런 우리말은 없다(http://terms.naver.com/entry.nhn?docId=982836&cid=85&categoryId=2641). 태학사. ISBN 9788959660148.Retrieved June 3, 2014.

4. Compare "liberty", a small local government unit in medieval England – the "local area under control".5. Exceptionally, in Japanese and Korean rules, empty points, even those surrounded by stones of a single color,

may count as neutral territory if some of them are alive by seki. See the section on "Life and Death" for seki.6. In game theoretical terms, seki positions are an example of a Nash equilibrium.7. Whether or not a group is weak or strong refers to the ease with which it can be killed or made to live. See

this article (http://senseis.xmp.net/?BenjaminTeuber%2FGuideToBecomeStrong:v52) by Benjamin Teuber,amateur 6 dan, for some views on how important this is felt to be.

8. A full explanation of the eternal life position can be found on Sensei's Library (http://senseis.xmp.net/?EternalLife), it also appears in the official text for Japanese Rules, see translation (http://www­2.cs.cmu.edu/~wjh/go/rules/Japanese.html).

9. Kaku Takagawa toured Europe around 1970, and reported (Go Review) a general standard of amateur 4 dan.This is a good amateur level but no more than might be found in ordinary Asian clubs. Published currentEuropean ratings would suggest around 100 players stronger than that, with very few European 7 dans.

10. European Go has been documented by Franco Pratesi, Eurogo (Florence 2003) in three volumes, up to 1920,1920–1950, and 1950 and later.

11. See Overshoot in Western typography for similar subtle adjustment to create a uniform appearance.12. Roughly, one has the time to play the game and then a little time to finish it off. Time­wasting tactics are

possible in Go, so that sudden death systems, in which time runs out at a predetermined point however manyplays are in the game, are relatively unpopular (in the West).

13. Literally in Japanese byōyomi means 'reading of seconds'.14. Typically, players stop the clock, and the player in overtime sets his/her clock for the desired interval, counts

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References

Citations

out the required number of stones and sets the remaining stones out of reach, so as not to become confused. Iftwenty moves are made in time, the timer is reset to five minutes again.

15. In other words, Canadian byoyomi is essentially a standard chess­style time control, based on N moves in atime period T, imposed after a main period is used up. It is possible to decrease T, or increase N, as eachovertime period expires; but systems with constant T and N, for example 20 plays in 5 minutes, are widelyused.

16. The number of board positions is at most 3361 (about 10172) since each position can be white, black, orvacant. Ignoring (illegal) suicide moves, there are at least 361! games (about 10768) since every permutationof the board positions corresponds to a game. See Go and mathematics for more details, which includes muchlarger estimates.

17. While chess position evaluation is simpler than Go position evaluation, it is still more complicated thansimply calculating material advantage or piece activity; pawn structure and king safety matter, as do thepossibilities in further play. The complexity of the algorithm differs per engine.

18. Lists of such programs may be found at Sensei's Library (http://senseis.xmp.net/?GoEditingPrograms) orGoBase (http://gobase.org/software/editors/).

19. Lists of Go servers are kept at Sensei's Library (http://senseis.xmp.net/?GoServers) and the AGA website(http://www.usgo.org/resources/servers.html)

20. The British Go Association provides a list of teaching services (http://www.britgo.org/teaching/teaching.html)21. A list of books can be found at Sensei's Library (http://senseis.xmp.net/?Literature)22. A list of films can de found at the EGF Internet Go Filmography

(http://www.eurogofed.org/history/filmography.htm)

1. "Info for School Teachers and other Youth Go Organisers" (http://www.britgo.org/youth/). British GoAssociation. Who can play go?. Retrieved 2011­08­10.

2. Burton, Watson (April 15, 1992). The Tso Chuan (reprint ed.). ISBN 978­0231067157.3. Fairbairn 19954. Brooks 20075. "OMNI Magazine" (June 1991).6. Matthews, Charles. Teach Yourself Go, p.17. Cho Chikun, p.188. Matthews, Charles. Teach Yourself Go, p.29. Iwamoto, p.2210. Iwamoto, p.1811. About the IGF (https://intergofed.org/about­the­igf.html), retrieved June 5, 201212. International Go Federation, IGF members (http://intergofed.org/members.html), retrieved June 5, 201213. Cobb p.1214. Cho Chikun, p.2115. Iwamoto, p.7716. Cho Chikun, p.2717. Cho Chikun, p.2818. Cobb p.2119. Cho Chikun, p.6920. Cobb p.2021. Cho Chikun, p.3522. "KGS Go Tutorial: Game End" (https://www.gokgs.com/tutorial/gameEnd.jsp). KGS. Retrieved 5 June 2014.23. Cho Chikun, p.10724. Iwamoto, p.9325. Cho Chikun, p.11926. Cho Chikun, p.3327. Cho Chikun, p.3728. "Hanami Ko at Sensei's Library" (http://senseis.xmp.net/?HanamiKo). Senseis.xmp.net. 2013­01­09.

Retrieved 2014­03­25.

03/09/2015 Go (game) ­ Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Go_(game) 26/31

Retrieved 2014­03­25.29. Iwamoto, p.10930. Cho Chikun, p.9131. Maschler, Michael (2013). Game Theory. Cambridge University Press. ISBN 978­1­107­00548­8.32. British Go Association, Comparison of some go rules (http://www.britgo.org/rules/compare.html), retrieved

2007­12­2033. NRICH Team, Going First (http://nrich.maths.org/public/viewer.php?obj_id=1470), University of

Cambridge, retrieved 2007­06­1634. Kim 1994 pp. 3–435. How to place Go stones (http://www.nihonkiin.or.jp/lesson/school­e/okikata­e.htm), Nihon Kiin, retrieved

2007­03­0436. Matthews, Charles, Behind the Rules of Go (http://nrich.maths.org/public/viewer.php?obj_id=1433),

University of Cambridge, retrieved 2008­06­0937. Kim 1994 p. 1238. Kim 1994 pp 48–4939. Kim 1994 pp. 144–14740. Ing rules of Go, translation archived by American Go Association website [1]

(http://www.usgo.org/files/pdf/IngRules2006.pdf), retrieved 5 August 201241. American Go Association Rules of Go. [2] (http://www.usgo.org/rules­go) retrieved 5 August 201242. Kim 1994 p. 3043. "Comparison of Some Go Rules" (http://www.britgo.org/rules/compare.html). British Go Association.

Retrieved 15 May 2014.44. Kim 1994 p. 2845. "A change in Komi" (http://www.usgo.org/aga­memo­regarding­komi). Retrieved 31 May 2014.46. "Life in 9x9: What is a reasonable komi value? • Life In 19x19" (http://gobase.org/studying/rules/?

id=6&ln=uk). Retrieved 31 May 2014.47. Fairbairn, John, "The Rules Debate" (http://www.gogod.co.uk/NewInGo/C&IP.htm), New in Go

(http://www.gogod.co.uk/NewInGo/NewInGo.htm), Games of Go on Disc, retrieved 2007­11­2748. Hansen, Fred, Demonstration of the Relationship of Area and Territory Scoring

(http://www.cs.cmu.edu/~wjh/go/rules/AGA.commentary.html), American Go Association, retrieved2008­06­16

49. Matthews 200250. Kim 1994 pp. 80–9851. Kim 1994 pp. 88–9052. Kim 1994 pp. 91–9253. Kim 1994 pp. 93–9454. Davies, James (1995). Tesuji. Elementary Go Series 3. Kiseido Publishing Company. p. 5. ISBN 4­906574­

12­2.55. Nakayama, Noriyuki (1984), "Memories of Kitani", The Treasure Chest Enigma, Slate & Shell, pp. 16–19,

ISBN 1­932001­27­156. van Zeijst, Rob, Whenever a player asks a top professional ...

(http://www.yomiuri.co.jp/dy/columns/0001/305.htm), Yomiuri Shimbun, retrieved 2008­06­0957. Tavernier, Karel (Spring 1998). "Analyzing Ko Struggles Theoretically"

(http://www.britgo.org/files/bgj/bgj110.pdf) (PDF). British Go Journal Nr. 110, Spring 1998, page 11.Retrieved 8 October 2013.

58. Baker, Karl (1986), The Way to Go, New York, NY: American Go Association59. Otake, Hideo (2002), Opening Theory Made Easy, Kiseido Publishing Company, ISBN 4­906574­36­X60. Ishigure, Ikuro (2006). In the Beginning: the Opening in the Game of Go. Elementary Go Series 1 (8 ed.).

Japan: Kiseido Publishing Company. p. 6. ISBN 4­906574­10­6.61. Ishida, Yoshio (1977), Dictionary of Basic Joseki, Kiseido Publishing Company62. In the Beginning (Beginner and Elementary Go Books). ISBN 978­4906574100.63. Risuke, Otake. Le Sabre et le Divin: Héritage spirituel de la Tenshin Shoden Katori Shint Ryu (in French).

p. 2. ISBN 978­2846170031.64. David, Ormerod. "Thinking big in Go" (http://gogameguru.com/thinking­big/). GoGameGuru. Retrieved

5 June 2014.65. David, Ormerod. "Go technique: Induction in the game of Go" (http://gogameguru.com/go­technique­

induction/). GoGameGuru. Retrieved 5 June 2014.66. Potter 198467. Yang, Lihui; Deming An, Jessica Anderson Turner (2005), Handbook of Chinese mythology

03/09/2015 Go (game) ­ Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Go_(game) 27/31

67. Yang, Lihui; Deming An, Jessica Anderson Turner (2005), Handbook of Chinese mythology(http://books.google.com/?id=Wf40ofEMGzIC&pg=PA228&dq=Yao+is+said+to+have+invented+the+game+of+Weiqi#v=onepage&q&f=false), ABC­CLIO Ltd, p. 228, ISBN 978­1­57607­806­8

68. Masayoshi 200569. Lasker 193470. Pickard 198971. History of Korean baduk (http://english.baduk.or.kr/sub01_01.htm?menu=f11), Korean Baduk Association,

retrieved 2008­11­1372. Fairbairn 200073. History of Go in Japan: part 2 (http://www.nihonkiin.or.jp/lesson/knowledge­e/history02.htm), Nihon Kiin,

retrieved 2007­11­0274. History of Go in Japan: part 3 (http://www.nihonkiin.or.jp/lesson/knowledge­e/history03.htm), Nihon Kiin,

retrieved 2007­11­0275. GoGoD (Fairbairn & Hall) (2007), "Timeline 1600–1867", History and Timelines76. GoGoD (Fairbairn & Hall) (2007), "Honinbo Dosaku", Articles on Famous Players77. GoGoD (Fairbairn & Hall) (2007), "Castle Games 1626–1863", History and Timelines78. Pinckard, William (1992), History and Philosophy of Go in Bozulich, 2001 pp. 23–2579. AGA 1995 Historical Book (http://www.usgo.org/archive/agahbk95.html), American Go Association, retrieved

2008­06­1180. Bozulich, Richard, The Magic of Go – 40. Go in Europe

(http://web.archive.org/web/20041011000303/http://www.yomiuri.co.jp/igo_e/040.htm), Yomiuri Shimbun,archived from the original (http://www.yomiuri.co.jp/igo_e/040.htm) on 2004­10­11, retrieved 2008­06­16

81. British Go Association, Pro Go Player visits to UK & Ireland (since 1964)(http://www.britgo.org/history/pros.html), retrieved 2007­11­17

82. Peng & Hall 199683. Go. The World's Most Fascinating Game, Tokyo, Japan: Nihon Kiin, 1973, p. 18884. Cieply, Ales, EGF Official Ratings (http://europeangodatabase.eu/EGD/EGF_rating_system.php#System),

European Go Federation (EGF), retrieved 2009­11­0685. EGF Tournament Database (http://www.europeangodatabase.eu/EGD/Player_Card.php?&key=12633346),

Association for Go in Italy (AGI), retrieved 2008­06­1986. The McMahon system in a nutshell

(http://web.archive.org/web/20080518202147/http://www.britgo.org/organisers/mcmahon.html), British GoAssociation, archived from the original (http://www.britgo.org/organisers/mcmahon.html) on 2008­05­18,retrieved 2008­06­11

87. GoGoD (Fairbairn & Hall) (2007), A quick guide to pro tournaments88. GoGoD (Fairbairn & Hall) (2007), "History of Komi", History and Timelines89. Jasiek, Robert (2001), Ko Rules (http://home.snafu.de/jasiek/korules.html), retrieved 2007­11­3090. Fairbairn, John. "MindZine ­ Go ­ Feature: Honinbo Jowa"

(http://web.archive.org/web/20110608002240/http://www.msoworld.com/mindzine/news/orient/go/history/jowa.html). Mind Sports WorldWide. Archived from the original(http://www.msoworld.com/mindzine/news/orient/go/history/jowa.html) on 9 July 2011. Retrieved 15 May2014.

91. Fairbairn, John, History of Newspaper Go (http://kopoint.files.wordpress.com/2012/12/go­the­game.pdf)(PDF), retrieved 2007­06­14

92. Go Seigen: Match Player (http://gobase.org/games/china/misc/disks/matches.html), GoBase.org, retrieved2007­06­14

93. Fairbairn, John, Kitani's Streak (http://senseis.xmp.net/?KitaniMinoru), retrieved 2007­06­1494. Fairbairn, John, Kubomatsu's central thesis (http://gobase.org/information/players/?

pp=Kubomatsu+Katsukiyo), retrieved 2008­01­1795. List of Japanese titles, prizemoney and winners (http://gobase.org/games/jp/), GoBase.org, retrieved

2008­06­1196. Kim, Janice, KBA Founder Cho Nam Chul passes (http://www.usgo.org/news/index.php?%23_id=102),

American Go Association, retrieved 2008­06­1197. Matthews, Charles, Weiqi in Chinese Culture

(http://www.societies.cam.ac.uk/cugos/tesuji/weiqi_chinese_culture.html), retrieved 2007­06­0498. Go The Board Game (http://kopoint.files.wordpress.com/2012/12/go­the­game.pdf) (PDF), retrieved

2008­06­11

03/09/2015 Go (game) ­ Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Go_(game) 28/31

99. "AGA Professional System" (http://www.usgo.org/aga­professional­system). usgo.org. Retrieved 3 March2015.

100. "1st European Pro Qualification 2014" (http://www.eurogofed.org/proqualification/). 2014. Retrieved11 January 2015.

101. List of International titles, prizemoney and winners (http://gobase.org/games/nn/), GoBase.org, retrieved2008­06­11

102. Shotwell, Peter (2003), Go! More Than a Game, Tuttle Publishing, ISBN 0­8048­3475­X103. Wimmer, Kerwin, Make Professional Shodan (http://www.britgo.org/bgj/04112.html), British Go

Association, retrieved 2008­06­11104. Fairbairn 1992 pp. 142–143105. Fairbairn 1992 pp. 143–149106. Kiseido clearance sale (http://www.kiseido.com/go_equipment.htm) lists the regular price for a Shihomasa

Kaya Go Board with legs (20.4 cm or 8.0 in thick) as $60,000+107. Fairbairn 1992 pp. 150–153108. Fairbairn 1992 pp. 153–155109. A stylish way to play your stones (http://www.nihonkiin.or.jp/lesson/knowledge­e/uchikata­e.htm), Nihon Ki­

in, retrieved 2007­02­24110. "Sensei's Library: Playing the first move in the upper right corner" (http://senseis.xmp.net/?

PlayingTheFirstMoveInTheUpperRightCorner). Senseis.xmp.net. 2011­09­19. Retrieved 2014­03­25.111. Bozulich 2001 pp. 92–93112. EGF General Tournament Rules (http://www.eurogofed.org/egf/tourrules.htm), European Go Federation,

retrieved 2008­06­11113. Stas Bekman: stas (at) stason.org. "Go FAQ" (http://stason.org/TULARC/games/go/5­3­Recording­Go­

games.html). Stason.org. Retrieved 2014­03­25.114. "Go markers" (http://www.unicode.org/charts/PDF/U2600.pdf#search=Go%20markers) (PDF). The Unicode

Standard.115. Top Ten Reasons to Play Go (http://www.usgo.org/resources/topten.html), American Go Association,

retrieved 2008­06­11116. O'Connor, J.J.; Robertson, E.F., Conway Biography (http://www­history.mcs.st­

andrews.ac.uk/Biographies/Conway.html), retrieved 2008­01­24117. Go Infinitesimals (http://senseis.xmp.net/?GoInfinitesimals)118. Wedd, Nick. "Human­Computer Go Challenges" (http://www.computer­go.info/h­c/index.html). computer­

go.info. Retrieved 2011­10­28.119. Johnson, George (1997­07­29), "To Test a Powerful Computer, Play an Ancient Game"

(http://query.nytimes.com/gst/fullpage.html?res=9C04EFD6123AF93AA15754C0A961958260), The NewYork Times, retrieved 2008­06­16

120. Overview of Computer Go(http://web.archive.org/web/20080531072850/http://www.intelligentgo.org/en/computer­go/overview.html),Intelligent Go Foundation, archived from the original (http://www.intelligentgo.org/en/computer­go/overview.html) on 2008­05­31, retrieved 2008­06­16

121. Keene, Raymond; Levy, David (1991), How to beat your chess computer, Batsford Books, p. 85122. Davey Alba (2014­06­17). "China's Tianhe­2 Caps Top 10 Supercomputers" (http://spectrum.ieee.org/tech­

talk/computing/hardware/tianhe2­caps­top­10­supercomputers). IEEE Spectrum. Retrieved 2014­24­14. Checkdate values in: |accessdate= (help)

123. Stern, David. "Modelling Uncertainty in the Game of Go"(http://web.archive.org/web/20130525131512/http://cs.brown.edu/~ynm/Papers/AAAI06­312.pdf) (PDF).Cornell University. Archived from the original (http://www.cs.brown.edu/~ynm/Papers/AAAI06­312.pdf)(PDF) on 15 May 2014. Retrieved 15 May 2014.

124. "Supercomputer with innovative software beats Go Professional"(http://www.cs.unimaas.nl/g.chaslot/muyungwan­mogo/). Retrieved 2008­12­19.

125. "AGA News: Kim Prevails Again In Man Vs Machine Rematch" (http://www.usgo.org/news/). Retrieved2009­08­08.

126. McDonald, Brian (2002) [1995], "Shibumi", in Shotwell, Peter, Go in Western Literature(http://web.archive.org/web/20060921171349/http://www.usgo.org/resources/downloads/go_in_literature.pdf)(PDF), American Go Association, pp. 5–6, archived from the original(http://www.usgo.org/resources/downloads/go_in_literature.pdf) (PDF) on 2006­09­21, retrieved 2008­06­16

127. Anderson, Troy (August 3, 2004), The Way of Go: 8 Ancient Strategy Secrets for Success in Business andLife

03/09/2015 Go (game) ­ Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Go_(game) 29/31

Bibliography

Bozulich, Richard (2001), The Go Player's Almanac (2nd ed.), Kiseido Publishing Company, ISBN 4­906574­40­8Brooks, E Bruce (2007), Warring States Project Chronology #2(http://www.umass.edu/wsp/project/introductions/chronology2.html), retrieved 2007­11­30Fairbairn, John (1992), A Survey of the best in Go Equipment in Bozulich 2001—pp. 142–155Fairbairn, John (1995), Go in Ancient China (http://www.pandanet.co.jp/English/essay/goancientchina.html),retrieved 2007­11­02Fairbairn, John (2000), History of Go in Korea

Life128. Yasuyuki, Miura (1998), Go, an Asian Paradigm for Business Strategy, Kiseido Publishing Company,

ISBN 4­906574­99­8129. Bozulich, Richard, The Magic of Go – 33. Go and business (1)

(https://web.archive.org/web/20041209075324/http://www.yomiuri.co.jp/igo_e/033.htm), Yomiuri Shimbun,archived from the original (http://www.yomiuri.co.jp/igo_e/033.htm) on 2004­12­09, retrieved 2013­11­27

130. Shotwell, p.176131. Shimatsuka, Yoko, Do Not Pass Go

(http://web.archive.org/web/20070610073841/http://www.asiaweek.com/asiaweek/magazine/nations/0,8782,132162,00.html), Asiaweek, archived from the original(http://www.asiaweek.com/asiaweek/magazine/nations/0,8782,132162,00.html) on 2007­06­10, retrieved2007­03­26

132. Scanlon, Charles (2002­08­01). "Young Japanese go for Go" (http://news.bbc.co.uk/2/hi/asia­pacific/2164532.stm). World News (BBC). Retrieved 2009­05­21.

133. Scott, A.O. (2007­03­14), "A Prodigy's Life Is Played Out In a Japanese Game of Skill"(http://query.nytimes.com/gst/fullpage.html?res=9D03EFDC1131F937A25750C0A9619C8B63&scp=1&sq=%22The+Go+Master%22&st=nyt), The NewYork Times, retrieved 2008­06­16

134. (film; 2013) Tokyo Newcomer135. Ng Ho (1998), "King Hu and the Aesthetics of Space", in Teo, Stephen, Transcending the Times:King Hu &

Eileen Chan, Hong Kong International Film Festival, Hong Kong: Provisional Urban Council of Hong Kong,p. 45

136. "The Rise and Fall of Atari" (http://www.neatorama.com/2008/05/05/the­rise­and­fall­of­atari/). RetrievedMay 5, 2014.

137. Spitznagel, Mark (2013). The Dao of Capital: Austrian Investing in a Distorted World. John Wiley & Sons.ISBN 978­1­1183­4703­4.

138. Gobet, F; de Voogt, A. J; Retschitzki, J (2004), Moves in Mind: The Psychology of Board Games(http://books.google.com/?id=fR7xZlGnyl0C&printsec=frontcover), Hove, UK: Psychology Press, ISBN 1­84169­336­7

139. Masunaga, H; Horn, J. (2001), "Expertise and age­related changes in components of intelligence", Psychologyand Aging 16 (16): 293–311, doi:10.1037/0882­7974.16.2.293 (https://dx.doi.org/10.1037%2F0882­7974.16.2.293)

140. Chen et al. (2003), "A functional MRI study of high­level cognition II. The game of GO"(http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6SYV­46YJ540­4&_user=10&_coverDate=03%2F31%2F2003&_alid=753089725&_rdoc=7&_fmt=high&_orig=search&_cdi=4844&_sort=d&_docanchor=&view=c&_ct=7&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=ccc4701dd97062447dcc4f5459b174dc), Cognitive Brain Research 16: 32, doi:10.1016/S0926­6410(02)00206­9 (https://dx.doi.org/10.1016%2FS0926­6410%2802%2900206­9), retrieved 2008­06­16

141. Verghese et al. (2003), "Leisure Activities and the Risk of Dementia in the Elderly"(http://content.nejm.org/cgi/content/abstract/348/25/2508), New England Journal of Medicine 348 (25): 2508–16, doi:10.1056/NEJMoa022252 (https://dx.doi.org/10.1056%2FNEJMoa022252), PMID 12815136(https://www.ncbi.nlm.nih.gov/pubmed/12815136)

142. Boorman, Scott A. (1969), The Protracted Game: A Wei Ch'i Interpretation of Maoist RevolutionaryStrategy, New York, NY: Oxford University Press, ISBN 0­19­500490­6

143. Pinckard, William, Go and the Three Games (http://www.kiseido.com/three.htm), Kiseido Publications,retrieved 2008­06­11 in Bozulich 2001

03/09/2015 Go (game) ­ Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Go_(game) 30/31

(http://web.archive.org/web/20110608021308/http://www.msoworld.com/mindzine/news/orient/go/history/origin_korea.html), archived from the original(http://www.msoworld.com/mindzine/news/orient/go/history/origin_korea.html) on 18 July 2011, retrieved15 May 2014Fairbairn, John; Hall, T Mark (2007), The GoGoD Encyclopaedia, Games of Go on DiscGao, Pat (2007). "Getting the Go­ahead" (http://taiwanreview.nat.gov.tw/ct.asp?xItem=24319&CtNode=1360).Taiwan review (Los Angeles, CA: Kwang Hwa Publishing) 57: 55.Kim, Janice; Jeong, Soo­hyun (1994), Learn to Play Go, Good Move Press, ISBN 0­9644796­1­3Lasker, Edward (1960) [1934], Go and Go­Moku, Courier Dover Publications, ISBN 0­486­20613­0Masayoshi, Shirakawa (2005), A Journey In Search of the Origins of Go, Yutopian Enterprises, ISBN 1­889554­98­7Matthews, Charles (September 2002), Sufficient but Not Necessary: Two Eyes and Seki in Go(http://nrich.maths.org/public/viewer.php?obj_id=1452), University of Cambridge, retrieved 2007­12­31Peng, Mike; Hall, Mark (1996), "One Giant Leap For Go"(http://web.archive.org/web/20120304121705/http://homepage.mac.com/bjornwendsjo/go/2­96.pdf) (PDF),Svenks Go Tidning 96 (2): 7–8, archived from the original (http://homepage.mac.com/bjornwendsjo/go/2­96.pdf) (PDF) on 2012­03­04, retrieved 2007­11­12

Potter, Donald L. (1984), "Go in the Classics" (http://www.kiseido.com/classics.htm), Go World (Tokyo: IshiPress) (37): 16–18, retrieved 2007­11­02Potter, Donald L. (1985), "Go in the Classics (ii): the Tso­chuan" (http://www.kiseido.com/classics.htm), GoWorld (Tokyo: Ishi Press) (42): 19–21, retrieved 2007­11­02Shotwell, Peter (2003), Go! More Than a Game, Tuttle Publishing, ISBN 0­8048­3475­X

Further reading

Introductory books

Baker, Karl. The Way to Go: How to Play the Asian Game of Go (http://www.usgo.org/way­go), AmericanGo Association, New York, rev. 7th ed., 2008, available as free .pdf download or e­book.Bradley, Milton N. Go for Kids, Yutopian Enterprises, Santa Monica, 2001 ISBN 978­1­889554­74­7.Cho, Chikun. Go: A Complete Introduction to the Game, Kiseido Publishers, Tokyo, 1997, ISBN 978­4­906574­50­6.Cobb, William. The Book of Go, Sterling Publishers, 2002, ISBN 978­0­8069­2729­9.Iwamoto, Kaoru. Go for Beginners, Pantheon, New York, 1977, ISBN 978­0­394­73331­9.Kim, Janice, and Jeong Soo­hyun. Learn to Play Go series, five volumes: Good Move Press, Sheboygan,Wisconsin, second edition, 1997. ISBN 0­9644796­1­3.Matthews, Charles. Teach Yourself Go, McGraw­Hill, 2004, ISBN 978­0­07­142977­1.Shotwell, Peter. Go! More than a Game, Tuttle Publishing, Boston, Revised 2010. ISBN 0­8048­3475­X.

Historical interest

Boorman, Scott A. (1969), The Protracted Game: A Wei Ch'i Interpretation of Maoist RevolutionaryStrategy, New York, NY: Oxford University Press, ISBN 978­0­19­501493­8De Havilland, Walter Augustus (1910), The ABC of Go: The National War Game of Japan, Yokohama, Kelly& Walsh, OCLC 4800147 (https://www.worldcat.org/oclc/4800147)Korschelt, Oscar (1966), The Theory and Practice of Go, C.E. Tuttle Co, ISBN 978­0­8048­0572­8Smith, Arthur (1956), The Game of Go: The National Game of Japan, C.E. Tuttle Co, OCLC 912228(https://www.worldcat.org/oclc/912228)

External links

Go (https://www.dmoz.org/Games/Board_Games/Abstract/Territory_Games/Go/) at DMOZInternational Go Federation (IGF) (http://www.intergofed.org/), at intergofed.orgEuropean Go Federation (EGF) (http://www.eurogofed.org/), at eurogofed.org

03/09/2015 Go (game) ­ Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Go_(game) 31/31

American Go Association (AGA) (http://www.usgo.org/), at usgo.orgThe Nihon Ki­in (Japan Go Association) (http://www.nihonkiin.or.jp/index­e.htm), atnihonkiin.or.jpHistory of Go (http://www.kiseido.com/three.htm)Sensei's Library (http://senseis.xmp.net/), a wiki about and around the game of GoGoproblems.com (http://www.goproblems.com/), open database of interactive Go problems, atgoproblems.comGo Game Guru (http://gogameguru.com/), frequently updated site where you can learn Go, studyGo and read Go newsDirect download for free print and play 9x9 Go set in A4(http://ocastudios.com/static/projects/classics/EN­bronze/go/releases/version­0­1­0/Classics­Go­0­1­0­EN.pdf) and letter (http://ocastudios.com/static/projects/classics/EN­bronze/go/releases/version­0­1­0/Classics­Go­0­1­0­US.pdf) formats.The Interactive Way to Go (http://playgo.to/iwtg/en/), an interactive tutorial for the Go game.GNU Go (http://www.gnu.org/software/gnugo/), a free text­mode Go engine program.qGo (http://qgo.sourceforge.net/), a free graphical user interface Go client, complete with a fullfeatured SGF editor.an ebook release by the American Go Association about the basics of Go.(http://www.usgo.org/files/pdf/W2Go4E­book.pdf,)

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Categories: Go (game) 2nd­millennium BC establishments in China

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