Yamamoto, Koki
Current rating: 1549
Record: 9-6
| Grand Prix Chiba 2019 (M20 limited) | starting rating: 1513 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 470 | Fujii, Mikiya (1319) | Won 2-0 | +151528 |
| 2sealed | 176 | Seki, Manabu (1421) | Won 2-0 | +161544 |
| 3sealed | 92 | Watanabe, Takefumi (1495) | Won 2-1 | +171561 |
| 4sealed | 201 | Qin, Yuxiang (1556) | Won 2-0 | +181579 |
| 5sealed | 46 | Hirayama, Atsushi (1694) | Lost 1-2 | -161563 |
| 6sealed | 83 | Matsuzaki, Kazuhisa (1532) | Won 2-1 | +171580 |
| 7sealed | 189 | Hosokawa, Yuya (1921) | Lost 1-2 | -121568 |
| 8sealed | 235 | Satou, Yoshinobu (1470) | Lost 0-2 | -191549 |
| average opponent: 1551record: 5-3 | new rating: 1549 | |||
| Grand Prix Chiba 2018 (M19 limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 474 | Suzuki, Kento (1471) | Won 2-0 | +171517 |
| 2sealed | 509 | Mori, Yuta (1427) | Lost 0-2 | -191498 |
| 3sealed | 861 | Arakawa, Tomohiro (1500) | Won 2-0 | +181516 |
| 4sealed | 692 | Kawamura, Naoki (1418) | Lost 0-2 | -201496 |
| 5sealed | 772 | Takeshita, Yuuki (1438) | Lost 0-2 | -191477 |
| 6sealed | 786 | Takagi, Tsubasa (1482) | Won 2-0 | +181495 |
| 7sealed | 628 | Hatanaka, Natsuki (1502) | Won 2-1 | +181513 |
| average opponent: 1462record: 4-3 | new rating: 1513 | |||