The Sanjubango Turning Point

July 1853. Edo, Japan. The sanjubango, a 30-game match between Ota Yuzo (7-dan) and Honinbo Shusaku (6-dan), was the most ambitious competitive series of the Edo period. Sponsored by the patron Akai Gorosaku after Ota disputed claims that Shusaku was the strongest player alive, it was played at a faster pace than a conventional jubango, roughly one game per week. Game 17, played on 10, 20, and 26 July 1853 (Kaei 6), became the turning point: 228 moves, White wins by three points.

The Match

Ota was 46 years old, a veteran of the Tempo Top Four and one of the few players who could challenge Shusaku on even terms. The series opened in March 1853 with Ota holding his own. Through the first ten games the score remained close. From the 11th game onward Shusaku accelerated, pulling ahead until Ota trailed by four games after the 17th. This game, in which Shusaku played White, was the one that broke Ota's resistance and forced the older master toward handicap in subsequent encounters.

Move 88

Commentators have singled out White 88 as the game's defining moment: a slow, thick reinforcement that ignored the temptation to invade prematurely and instead solidified Shusaku's position with such efficiency that, in the traditional gloss, it seemed to say "just this is enough to win." The move is not a flashy tesuji but a statement of confidence, the kind of play that separates Shusaku from players who needed complications to thrive.

End of the Series

The sanjubango was officially abandoned after 23 games when Shusaku was called up for castle games and Ota had fallen too far behind. Tradition holds that the 23rd game, a marathon lasting nearly 24 hours, ended in a jigo that spared Ota further embarrassment, though historians treat that account as anecdotal rather than proven. Ota died in 1855, two years after the match. Shusaku went on to win all 19 of his official castle games and is remembered as the strongest player of the late Edo period until his death in 1862.

Primary sources for this account include the CWI Amsterdam Shusaku archive (30-game match, game 17, RE[W+3], 228 moves), John Power's Invincible, Wikipedia biographies of Shusaku and Ota Yuzo, and VitWiki's famous games index.