Title Matches Played
March through April
Sankei Shinbun
Nihon Ki-in
Kansai Ki-in
Best of
Time Allotted (Title)
3 hours
Byouyomi (Title)
5 minutes
Time Allotted (League)
3 hours
Byouyomi (League)
5 minutes

The Juudan tournament is a Japanese professional go competition featuring a challenge against the Juudan for his title.

Until 2011, players competed in a a 16-player league tournament for the right to challenge the Juudan.

Preliminaries were held by the Nihon Ki-in:

  1. The B/C preliminaries:
    • 26 players from the Tokyo branch
    • 10 players from the Kansai and Chubu branches (combined)
  2. The A preliminary:
    • 13 players from the Tokyo branch
    • 5 players from the Kansai and Chubu branches (combined)
  3. The final preliminaries:
    • 8 players from the A preliminary
    • 14 players seeded from last year's tournament

The Juudan used a double-knockout system. Under this system, a player who lost a game in the league tournament was knocked down to a parallel losers' tournament. The winner of the main tournament and the winner of the parallel losers' tournament played to determine who had the right to challenge the Juudan.

The winner of the series gains (or retains) the title of Juudan.

The top eight players were seeded in the league for the next year's Juudan tournament.

In 2012, the format of the Juudan changed significantly. As of 2012, the Juudan is a 20-player league single-knockout tournament. The two semifinalists are seeded in next year's tournament.

"Juudan" 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 22 months to progress from Preliminary C to the final title match.

  • Preliminary C
    • July through September (first year)
  • Preliminary B
    • October through December (first year)
  • Preliminary A
    • January through March (second year)
  • Last Preliminary
    • April through June (second year)
  • Main Tournament
    • July (second year) through February (third year)
  • Title Matches
    • March through April (third year)


January A Preliminary Main Tournament
February A Preliminary Main Tournament
March A Preliminary Title Matches
April Last Preliminary Title Matches
May Last Preliminary
June Last Preliminary
July C Preliminary Main Tournament
August C Preliminary Main Tournament
September C Preliminary Main Tournament
October B Preliminary Main Tournament
November B Preliminary Main Tournament
December B Preliminary Main Tournament


Title Challengers