Koshiko, Yuuya
Current rating: 1497
| Grand Prix Chiba 2019 (M20 limited) | starting rating: 1512 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 216 | Yuasa, Kentarou (1488) | Won 2-1 | +181530 |
| 2sealed | 164 | Kutsukake, Takuro (1670) | Lost 1-2 | -161514 |
| 3sealed | 621 | Aoyama, Yuki (1392) | Draw 1-1 | -21512 |
| 4sealed | 770 | Akaike, Yo (1707) | Lost 1-2 | -151497 |
| top | average opponent: 1564record: 1-2-1 | new rating: 1497 | ||
| Grand Prix Yokohama 2019 (modern) | starting rating: 1460 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 568 | Tanaka, Jouji (1574) | Won 2-0 | +201480 |
| 2modern | 434 | Shen, Yufei (1533) | Lost 1-2 | -171463 |
| 3modern | 855 | Ebana, Yusuke (1501) | Won 2-1 | +181481 |
| 4modern | 513 | Minotani, Jun (1582) | Won 2-0 | +201501 |
| 5modern | 164 | Kamioka, Masayuki (1591) | Won 2-0 | +201521 |
| 6modern | 142 | Taga, Tomonori (1531) | Lost 0-2 | -181503 |
| 7modern | 323 | Mochizuki, Yosuke (1552) | Won 2-1 | +191522 |
| 8modern | 150 | Hayashi, Shinsuke (2000) | Lost 1-2 | -101512 |
| top | average opponent: 1608record: 5-3 | new rating: 1512 | ||
| Grand Prix Chiba 2016 (legacy) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 134 | Nakagawa, Hikaru (1522) | Lost 1-2 | -181482 |
| 2legacy | 629 | Hayashi, Ryuichiro (1431) | Won 2-1 | +171499 |
| 3legacy | 888 | Noto, Yoshinari (1329) | Lost 1-2 | -211478 |
| 4legacy | 855 | Odagiri, Mato (1433) | Lost 0-2 | -181460 |
| top | average opponent: 1429record: 1-3 | new rating: 1460 | ||