Tagai-sen
Keywords: Go term
互い先 (tagai-sen) is a Japanese go term which describes the phase in a series of matches between two players - like a jubango, where they take Black on turns. This is an even phase. Usually, after three games in a row are won by the same player, or some other threshold, the handicap shifts to sen-ai-sen. A game which if lost would result in a shift in the handicap is called a kadoban.