|Title Matches Played|
|October through December|
|Nihon Keizai Shinbun|
|Time Allotted (Title)|
|Time Allotted (League)|
The Ouza tournament is a Japanese professional go competition featuring a challenge against the Ouza for his title.
C through B Preliminaries
Players from the Kansai Ki-in and the Chuubu branch of the Nihon Ki-in compete in a separate set of single-knockout preliminaries, advancing from C to B. The top 10 players qualify for the A preliminary.
The last preliminary is a single-knockout tournament comprised of 34 players, including:
- The 13 players who qualified in the A preliminary held by the Nihon Ki-in for players of its Tokyo main branch.
- The 5 players who qualified in the A preliminary held jointly by the Kansai Ki-in for its players and the Nihon Ki-in for the players of its Chuubu branch.
The top 11 players progress to the main tournament.
The main tournament is a single-knockout tournament comprised of 16 players:
- The 11 players who qualified in the last preliminary
The winner advances to the title challenge.
The winner of the playoff challenges the Ouza for his title in a best-of-5 series. The winner of the series gains (or retains) the title of Ouza, and will await next year's challenger.
"Ouza" may be assumed as an honourary title by players who have won the title 10 times in a row, or at the age of 60 or at retirement by players who have mounted 5 successful sequential defences of the title.
It takes 21 months to progress from Preliminary C to the final title match.
- Preliminary C
- April through June (first year)
- Preliminary B
- July through September (first year)
- Preliminary A
- October through December (first year)
- Last Preliminary
- January through March (second year)
- Main Tournament
- April through September (second year)
- Title Matches
- October through December (second year)
|April||C Preliminary||Main Tournament|
|May||C Preliminary||Main Tournament|
|June||C Preliminary||Main Tournament|
|July||B Preliminary||Main Tournament|
|August||B Preliminary||Main Tournament|
|September||B Preliminary||Main Tournament|
|October||A Preliminary||Title Matches|
|November||A Preliminary||Title Matches|
|December||A Preliminary||Title Matches|