Ko fight

A ko fight (Japanese: コウ, 劫, kō, from the translation of the Sanskrit term kalpa) 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 repetition of position, by a short 'loop' in which a single stone is captured, and another single stone immediately taken back. The rule states that a repetition of position is forbidden, and sometimes recapturing a stone would cause such a position. 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. Then the ban has come to its end, and recapture is possible. This kind of distracting play is termed a ko threat. If White, say, chooses to play a ko threat, and Black responds to the threat instead of ending the ko in some fashion, then White can recapture the stone that began the ko. This places Black in the same position that White was formerly in: Black can choose to give up the ko, or to find a ko threat. If Black and White alternate making ko threats with recapturing the ko, they are having a ko fight. Eventually, one of three things will happen.