(本因坊リーグ) The Honinbo League is the eight-player round robin (all-play-all) tournament to determine who the challenger will be for the Honinbo title in Japan.
Each year the four lowest-placing league members lose their places in the league. Their replacements are selected through knock-out preliminary tournaments, with the bottom finishers in the league seeded into the final stage. For example, in the 76th edition Sada Atsushi scored 2-5 in the league and was eliminated, then in the 77th edition he beat three opponents in the final preliminary and regained a seat in the league.
The loser of the title match becomes a league member for the next year's challenger selection.