|Title Matches Played|
|May through July|
|Time Allotted (Title)|
|Time Allotted (League)|
The Hon'inbou tournament is a Japanese professional go competition featuring a challenge against the Hon'inbou 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 16 players qualify for the A preliminary.
The last preliminary is a single-knockout tournament comprised of 36 players, including:
- The 20 players who qualified in the A preliminary held by the Nihon Ki-in for players of its Tokyo main branch.
- The 8 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 4 players who were bottom-most ranked in last year's league and lost their places in the league.
The top 4 players progress to the league.
The league is comprised of 8 players:
- The top 4 players from last year's league
- The 4 qualifying players from the last preliminary
The league plays a round-robin tournament, and players are ranked based on performance.
- The bottom 4 players lose their positions in the league and are returned to the last preliminary
- The top player progresses to the title challenge
In the event that two players tie for top performance in the league, the two tied players advance to a playoff.
In the event that players are tied for the top position in the league, the tied players will advance to a playoff to determine who earns the right to challenge the Hon'inbou. The winner advances to the title challenge.
The winner of the playoff challenges the Hon'inbou for his title in a best-of-7 series. The winner of the series gains (or retains) the title of Hon'inbou, and will await next year's challenger.
Players who have mounted 5 successful sequential defences of the title are named Hon'inbou (numbered in sequence after the heads of the Hon'inbou school of go before it passed the title to the Nihon Ki-in in 1940). This is distinct from being recognized as the current holder of the Hon'inbou title. As there were 21 heads of the Hon'inbou school, the numbering for modern-day players who have achieved the status of honourary Hon'inbou resumes at 22, e.g., 22nd Hon'inbou Takagawa Kaku.
It takes 24 months to progress from Preliminary C to the final title match.
- Preliminary C
- August through October (first year)
- Preliminary B
- November (first year) through January (second year)
- Preliminary A
- February through April (second year)
- Last Preliminary
- May through September (second year)
- League Tournament
- October (second year) through April (third year)
- Title Matches
- May through July (third year)
|January||B Preliminary||League Tournament|
|February||A Preliminary||League Tournament|
|March||A Preliminary||League Tournament|
|April||A Preliminary||League Tournament|
|May||Last Preliminary||Title Matches|
|June||Last Preliminary||Title Matches|
|July||Last Preliminary||Title Matches|
|August||C Preliminary||Last Preliminary|
|September||C Preliminary||Last Preliminary|
|October||C Preliminary||League Tournament|
|November||B Preliminary||League Tournament|
|December||B Preliminary||League Tournament|