is the second oldest of the seven big titles in Japanese professional Go. The tournament is organised by the Japanese Nihon Ki-in and sponsored by the Nihon Keizai Shinbun, also known as The Nikkei. The six other big Go titles include the Kisei, Meijin, Honinbo, Judan, Tengen, and the Gosei.
As of 2026, there have been 73 iterations of the OzÃÂ tournament since 1953. The winner's prize is currently ÃÂ¥14,000,000, ranking it fourth largest among the big seven. All professional players of the Nihon Ki-in and Kansai Ki-in can participate in the OzÃÂ.
The OzÃÂ has a similar format to other big Go tournaments in Japan. Since the 16th OzÃÂ in 1968, the winner of a preliminary tournament, played in single knockout, advances to play a best-of-five match against the previous year's title holder. Previously, the tournament format was a best-of-three match between two final players from the knockout rounds.