Quadruple Ko

    Keywords: Ko, Go term

Chinese: 四劫 (sì jié); or 四劫循环 (sì jié xún huán)
Japanese: 四コウ (yon kō)
Korean: 사패 (sa pae)

Similar to triple ko, a quadruple ko involves four kos on the board that are all in play at the same time. Often they are part of the same configuration, as in this example.

[Diagram]

An example of quadruple ko


A double ko and two separate kos can also form a quadruple ko.

A quadruple ko may lead to a game ending in no result if neither player is willing to back down from the ko fight, though some modern rulesets handle it with the superko rule. It is reported that a total of eight quadruple kos have occurred in professional Japanese play.

Examples

  • In the preliminaries for the 25th Kisei, the game on April 6th 2000 between Doi Makoto and Hasegawa Sunao ended in no result due to a quadruple ko that occurred relatively early in the game. The game was replayed, with Hasegawa winning. [ext] SGF.
  • An amateur game from the 2003 Frankfurt Go Tournament (Simon Kober 16 kyu versus Bjoern Wenzlaff 18 kyu) also included a quadruple ko. A photo is on the cover of [ext] DGoZ 3/2003.

See also:


This is a copy of the living page "Quadruple Ko" at Sensei's Library.
(OC) 2012 the Authors, published under the OpenContent License V1.0.
[Welcome to Sensei's Library!]
StartingPoints
ReferenceSection
About