Sen Ni Sen
Keywords: Culture & History, Tournament
先二先 (sen ni sen) is a Japanese go term describing the handicap in a series of matches between two players - like a jubango, where one player takes Black in two games out of three and a two stone handicap in the other game.
In the older system of pro handicapping, this was considered correct for players three dan levels apart. [1]
Used in jubango and the discontinued Oteai.
[1] On average, sen-ni-sen gives Black a 5/6 move's advantage.