Ko fight

A ko (Japanese: コウ, 劫, kō, from the translation of the Sanskrit term kalpa) fight is a tactical and strategic phase that can arise in the game of Go.

The existence of ko fights is implied by the rule of ko, a special rule of the game that prevents immediate repetition of position, by a short 'loop' in which a single stone is captured, and another single stone immediately taken back.

This gives rise to the following procedure: the 'banned' player makes a play, which may have no particular good qualities, but which demands an instant reply.

A double ko is a situation when two kos are potentially being fought, simultaneously and affecting the same local position.

Such positions are uncommon, but do sometimes arise in actual play, affecting life and death or connection issues.

When there are three kos on the board, it does not follow that there will be a triple ko: as long as one player can concede two out of three and still be ahead, there is no reason for the loop to persist; and normally that is true.

Such events, however, are extremely uncommon and many go players may play their whole lives without restarting a game due to a triple ko.