66th Honinbo
The 66th Honinbo began league play on 7 October 2010 and completed on July 21, 2011. Title holder Yamashita Keigo retained his title over challenger Hane Naoki by a score of 4-3. Yamashita Keigo won the first three games, Hane Naoki the next three, and Yamashita Keigo the final game.[1]
Preliminary tournament
The preliminary tournament started on 8 April 2010. Hane Naoki, Iyama Yuta, Takao Shinji, and Cho U retained their place in the Honinbo league from the 65th Honinbo. These players were joined by the winners of the preliminary tournament: Cho Sonjin, Seto Taiki, O Rissei, and Kobayashi Satoru.
| Quarter-finals | Semi-finals | Final | ||||||||
| 13 May | ||||||||||
| Yamashiro Hiroshi | 1 | |||||||||
| 17 June | ||||||||||
| Fujita Akihiko | 0 | |||||||||
| Yamashiro Hiroshi | 1 | |||||||||
| 27 May | ||||||||||
| Takashima Takeshi | 0 | |||||||||
| Goto Shungo | 0 | |||||||||
| 12 August | ||||||||||
| Takashima Takeshi | 1 | |||||||||
| Yamashiro Hiroshi | 0 | |||||||||
| 20 May | ||||||||||
| Cho Sonjin | 1 | |||||||||
| Ohashi Hirofumi | 0 | |||||||||
| 1 July | ||||||||||
| Uchida Shuhei | 1 | |||||||||
| Uchida Shuhei | 0 | |||||||||
| 27 May | ||||||||||
| Cho Sonjin | 1 | |||||||||
| Cho Sonjin | 1 | |||||||||
| Yamada Kimio | 0 | |||||||||
| Quarter-finals | Semi-finals | Final | ||||||||
| 13 May | ||||||||||
| Hoshino Masaki | 0 | |||||||||
| 10 June | ||||||||||
| Kataoka Satoshi | 1 | |||||||||
| Kataoka Satoshi | 1 | |||||||||
| 13 May | ||||||||||
| Obuchi Morito | 0 | |||||||||
| Obuchi Morito | 1 | |||||||||
| 29 July | ||||||||||
| Yasuda Yasutoshi | 0 | |||||||||
| Kataoka Satoshi | 0 | |||||||||
| 13 May | ||||||||||
| Seto Taiki | 1 | |||||||||
| Yamada Noriyoshi | 0 | |||||||||
| 24 June | ||||||||||
| Akiyama Jiro | 1 | |||||||||
| Akiyama Jiro | 0 | |||||||||
| 27 May | ||||||||||
| Seto Taiki | 1 | |||||||||
| Seto Taiki | 1 | |||||||||
| Mimura Tomoyasu | 0 | |||||||||
| Quarter-finals | Semi-finals | Final | ||||||||
| 13 May | ||||||||||
| Nakane Naoyuki | 0 | |||||||||
| 24 June | ||||||||||
| Nakano Hironari | 1 | |||||||||
| Nakano Hironari | 0 | |||||||||
| 3 June | ||||||||||
| Kono Rin | 1 | |||||||||
| Ogata Masaki | 0 | |||||||||
| 2 September | ||||||||||
| Kono Rin | 1 | |||||||||
| Kono Rin | 0 | |||||||||
| 20 May | ||||||||||
| O Rissei | 1 | |||||||||
| O Rissei | 1 | |||||||||
| 15 July | ||||||||||
| Mochizuki Kenichi | 0 | |||||||||
| O Rissei | 1 | |||||||||
| 27 May | ||||||||||
| Yuki Satoshi | 0 | |||||||||
| Kamimura Haruo | 0 | |||||||||
| Yuki Satoshi | 1 | |||||||||
| Quarter-finals | Semi-finals | Final | ||||||||
| 22 April | ||||||||||
| O Meien | 0 | |||||||||
| 10 June | ||||||||||
| Kobayashi Satoru | 1 | |||||||||
| Kobayashi Satoru | 1 | |||||||||
| 13 May | ||||||||||
| Ishida Atsushi | 0 | |||||||||
| Shida Tatsuya | 0 | |||||||||
| 19 August | ||||||||||
| Ishida Atsushi | 1 | |||||||||
| Kobayashi Satoru | 1 | |||||||||
| 3 June | ||||||||||
| Suzuki Shinji | 0 | |||||||||
| Mizokami Tomochika | 0 | |||||||||
| 24 June | ||||||||||
| Suzuki Shinji | 1 | |||||||||
| Suzuki Shinji | 1 | |||||||||
| 13 May | ||||||||||
| Cho Chikun | 0 | |||||||||
| Cho Chikun | 1 | |||||||||
| Takemiya Masaki | 0 | |||||||||
League play
League play commenced on 7 October after the preliminaries, which finished on 2 September. Hane Naoki, who lost the Honinbo title to Yamashita Keigo the year prior, won the right to challenge Keigo for the title.[1]
| Player | H.N. | I.Y. | T.S. | C.U. | O.R. | K.S. | C.S. | S.T. | Record | Notes |
|---|---|---|---|---|---|---|---|---|---|---|
| Hane Naoki | – | B+R | W+R | X | W+0.5 | B+R | W+R | B+R | 6–1 | Challenger |
| Iyama Yuta | X | – | B+R | X | X | W+R | B+R | W+R | 4–3 | |
| Takao Shinji | X | X | – | B+1.5 | X | X | W+R | X | 2–5 | Eliminated |
| Cho U | W+R | B+0.5 | X | – | B+3.5 | X | B+R | X | 4–3 | |
| O Rissei | X | W+R | B+R | X | – | X | X | B+R | 3–4 | Eliminated |
| Kobayashi Satoru | X | X | W+2.5 | B+4.5 | W+R | – | X | X | 3–4 | Eliminated |
| Cho Sonjin | X | X | X | X | B+R | W+11.5 | – | X | 2–5 | Eliminated |
| Seto Taiki | X | X | W+R | B+R | X | B+3.5 | W+R | – | 4–3 |
Finals
| Yamashita Keigo (Honinbo) | W+7.5 | B+R | W+1.5 | W+4.5 | 4 | |||
| Hane Naoki (Challenger) | W+0.5 | B+R | W+7.5 | 3 |