Yahata Koichi
Yahata Koichi (八幡幸一) has a rating of 1491. Their highest rating so far is 1529 (November 19, 2016).
Retired. The rating shown is the rating at retirement.
- 2017 record
- 1-2
- Record since 1927
- 8-9
- Win rate
- .471
Rating at retirement (not included in the rating list)
The rating is calculated from published game results. It does not include any adjustment for playing Black.
Professional ratingsFind a player
Rating history — professional
The “All” view starts at 2006; earlier years are used only to warm up the calculation and are not shown.
Recent games
| Date | Opponent and tournament | Result | Change |
|---|---|---|---|
| December 14, 2017 | Hara MasakazuKisei First Tournament Preliminary Round 2 Colors unknown | Loss | ↓12 |
| December 6, 2017 | Yamazaki YoshihiroKisei First Tournament Preliminary Round 2 Colors unknown | Loss | ↓15 |
| November 16, 2017 | Tsukuda AkikoKisei First Tournament Preliminary Round 1 Colors unknown | Win | ↑11 |
| December 14, 2016 | Hara MasakazuKisei First Tournament Round 2 as White | Loss | ↓12 |
| December 3, 2016 | Shimojima YoheiKisei First Tournament Preliminary Round 2 Colors unknown | Loss | ↓9 |
| November 19, 2016 | Oda TeppeiKisei First Tournament Preliminary Round 1 Colors unknown | Win | ↑11 |
| March 11, 2016 | Yu ZhengqiKisei First Tournament Preliminary Semifinal Colors unknown | Loss | ↓1 |
| January 21, 2016 | 趙錫彬Kisei First Tournament Preliminary Round 2 Colors unknown | Win | ↑13 |
| December 26, 2015 | Inoue AyakoKisei First Tournament Preliminary Round 1 Colors unknown | Win | ↑16 |
| June 23, 2005 | Okumura YasushiKisei Colors unknown | Loss | ↓17 |
| September 23, 2004 | Sasaki TsuyoshiKisei Colors unknown | Loss | ↓14 |
| August 19, 2004 | Takeda YoshinoriKisei Colors unknown | Win | ↑11 |
| July 8, 2004 | Ota MasahitoKisei Colors unknown | Win | ↑8 |
| August 6, 2003 | Nagasaki YujiKisei Colors unknown | Loss | ↓16 |
| July 16, 2003 | Yamada ShihoKisei Colors unknown | Win | ↑17 |
| June 12, 2003 | Mikawa ShinjiKisei Colors unknown | Win | ↑18 |
| January 12, 1994 | Kono TakashiShinjin-O as White | Loss | ↓17 |
Head-to-head
| Opponent | Total | As Black | As White |
|---|---|---|---|
| Hara Masakazu | 0-2.000 | 0-0 | 0-1 |
| Shimojima Yohei | 0-1.000 | 0-0 | 0-0 |
| Tsukuda Akiko | 1-01.000 | 0-0 | 0-0 |
| Yamada Shiho | 1-01.000 | 0-0 | 0-0 |
| Takeda Yoshinori | 1-01.000 | 0-0 | 0-0 |
| Yu Zhengqi | 0-1.000 | 0-0 | 0-0 |
| Mikawa Shinji | 1-01.000 | 0-0 | 0-0 |
| Inoue Ayako | 1-01.000 | 0-0 | 0-0 |
| 趙錫彬 | 1-01.000 | 0-0 | 0-0 |
| Nagasaki Yuji | 0-1.000 | 0-0 | 0-0 |
Record by year
Counted by calendar year, January to December (default wins and losses are included; jigo and no-result games are not). Only games from 1927 onward are counted, so these totals do not match the career records published by the two Ki-in.
| Year | Record | Win rate |
|---|---|---|
| 2017 | 1-2 | .333 |
| 2016 | 2-3 | .400 |
| 2015 | 1-0 | 1.000 |
| 2005 | 0-1 | .000 |
| 2004 | 2-1 | .667 |
| 2003 | 2-1 | .667 |
| 1994 | 0-1 | .000 |
| Total | 8-9 | .471 |
Calculated from games played between 1927 and 2026 (as of September 17, 2026).