Bob McGuigan: A note at the end of the main page asks for more information about Go Seigen's Jubango matches and other modern matches. Historically the multi-game matches were either challenge matches (sogo) or else "friendly" matches, possibly between fellow house-members, or even series of teaching games, as was the 20 game match between Sekiyama Sendaiu and Shusaku. Once the 20th century professional go associations were formed there was little need for challenge matches to settle rank disputes, the office of godokoro had been abolished, and after Shusai's death the title of Meijin was awarded through tournament play. Go Seigen's ten game matches were arranged by the Yomiuri newspaper, in part because Go was not allowed to compete in major tournaments. So, by mid-twentieth century there was little need for challenge matches. As the number of tournaments increased, title matches took the place of challenge matches.