Kubomatsu Katsukiyo
Kubomatsu Katsukiyo 久保松勝喜代 (1894-1941) - the 'great amateur'. 7 dan according to Gobase game records. Innovator in fuseki, teacher of a large group of pupils (including Kitani). Renju? 8 dan, inventor of ninuki renju?.
Kubomatsu was promoted 9 dan in 2009 (68 years after his death) by Nihon Kiin and by Kansai Kiin. Here is the new
Sakata Eio writes in Killer of Go: ''"Also, there is the matter of the late, great master of the Osaka area, Kubomatsu Katsukiyo. Master Kubomatsu's flair was for creating immense stretches of territory in the center. If one has the opportunity to play out a game of this master of old, it is recommended that one do so."'' Also, he was the first modern player extensively experimenting with tengen opening (see John Fairbairn's article below).
John Fairbairn MindZine article: http://www.msoworld.com/mindzine/news/orient/go/history/kubomatsu.html
Pasky: Why "the great amateur"? According to John Fairbairn's article he was playing in Oteai, so he must have been a pro?