Jump to content

Gomoku

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Manslay (talk | contribs) at 08:43, 8 August 2012 (Sergey Chernov link leads to someone else. Made it link to ru-wiki). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Gomoku is an abstract strategy board game. Also called Gobang or Five in a Row, it is traditionally played with Go pieces (black and white stones) on a go board (19x19 intersections)[attribution needed]; however, because once placed, pieces are not moved or removed from the board, gomoku may also be played as a paper and pencil game. This game is known in several countries under different names.

Black plays first, and players alternate in placing a stone of their color on an empty intersection. The winner is the first player to get an unbroken row of five stones horizontally, vertically, or diagonally.

Origin

The name "Gomoku" is from the Japanese language, in which it is referred to as gomokunarabe (五目並べ). Go means five, moku is a counter word for pieces and narabe means line-up. The game is also popular in Korea, where it is called omok (오목(五目)) which has the same structure and origin as the Japanese name. It is said to have originated in China with the name Wu Zi Qi (五子棋). In the nineteenth century, the game was introduced to Britain where it was known as Go Bang, said to be a corruption of Japanese goban, said to be adopted from Chinese k'i pan (qí bàn) 'chess-board'.[1]

Variations and opening rules

Black was long known to have a big advantage, even before L. Victor Allis proved that black could force a win (see below). So a number of variations are played with extra rules that aimed to reduce black's advantage.

Gomoku

  • Standard gomoku requires a row of exactly five stones for a win: rows of six or more, called overlines, do not count.
  • Free-style gomoku is the basic game as described above.

Caro

  • In Caro, popular among Vietnamese, the winner must have an unbroken row of five stones and this row must not be blocked at both ends. This rule makes Gomoku more flexible and provides more power for White to defend.

Omok

  • Omok is played the same as Standard Gomoku; however, it is played on a 15×15 board and does not include the rule of four and four. The overlines and three and three rules still apply.

Other similar games

  • The rule of three and three bans a move that simultaneously forms two open rows of three stones (rows not blocked by an opponent's stone at either end).
  • The rule of four and four bans a move that simultaneously forms two rows of four stones (open or not).
  • Renju is played on a 15×15 board, with the rules of three and three, four and four, and overlines applied to black only. There are special rules for the opening.
  • Ninuki-renju or Wu is a variant which adds capturing to the game; it was published in the USA in a slightly simplified form under the name Pente.
  • m,n,k-games are a generalization of gomoku to a board with m×n intersections, and k in a row needed to win.
  • Connect(m,n,k,p,q) games are another generalization of gomoku to a board with m×n intersections, k in a row needed to win, p stones for each player to place, and q stones for the first player to place for the first move only. Each player may play only at the lowest unoccupied place in a column. Connect(m,n,6,2,1) is the most interesting one, and is called Connect6.

The only fair opening rule currently is swap2 based on swap from Renju and first seen on kurnik.org. The first player places 3 stones (2 black 1 white, if black goes first) on the board, the second player has the choice to take black/white or place 2 more stones to change the shape and let the first player choose color. This is essentially a slightly more elaborate pie rule.

Analysis

Computer search by L. Victor Allis has shown that on a 15×15 board, black wins with perfect play.[2] This applies regardless of whether overlines are considered as wins, but it assumes that the rule of three and three is not used. It seems very likely that black wins on larger boards too.[citation needed] In any size of a board, freestyle gomoku is an m,n,k-game, and it is known that the second player does not win. With perfect play, either the first player wins or the result is a draw.

Generalized gomoku is PSPACE-complete.[3]

World championships

World Championships in Gomoku have occurred 2 times in 1989, 1991[1]. Since 2009 the tournament resumed, the opening rule being played was changed and now is swap2.

List of the tournaments occured and title holders follows.

Title year Hosting city, country Champion Opening rule
1989 Kyoto Japan Soviet Union Sergey Chernov Gomoku pro (3rd outside 5X5)
1991 Moscow Soviet Union Soviet Union Yuri Tarannikov Gomoku pro (3rd outside 5X5)
2009 Pardubice Czech Republic Poland Artur Tamiola Gomoku swap2
2011 Huskvarna Sweden Hungary Attila Demján Gomoku swap2

See also

References

  1. ^ OED citations: 1886 GUILLEMARD Cruise ‘Marchesa’ I. 267 Some of the games are purely Japanese..as go-ban. Note, This game is the one lately introduced into England under the misspelt name of Go Bang. 1888 Pall Mall Gazette 1. Nov. 3/1 These young persons..played go-bang and cat's cradle.
  2. ^ L. Victor Allis (1994). Searching for Solutions in Games and Artificial Intelligence (PDF). Ph.D. thesis, University of Limburg, The Netherlands. ISBN 90-900748-8-0.
  3. ^ Stefan Reisch (1980). "Gobang ist PSPACE-vollständig (Gomoku is PSPACE-complete)". Acta Informatica. 13: 59–66.
Further reading
  • Five-in-a-Row (Renju) For Beginners to Advanced Players ISBN 4-87187-301-3
Retrieved from "https://en.wikipedia.org/w/index.php?title=Gomoku&oldid=506362515"