The Jūdan (十段, "10 dan") is a Go competition in Japan.
In the Jūdan competition, if a player wins the challenger section, they are promoted to 7 dan.
Winning the title gives the player a promotion to 8 dan.
If the player subsequently wins another of the second tier top titles (Gosei, Judan, Oza, Tengen), the player will be promoted to 9 dan.
[2] The competition had a predecessor, named Hayago Meijin, that ran from 1956 to 1961.