Koga, Akira
Current rating: 1449
Record: 12-16
| Grand Prix Nagoya 2019 (ELD standard) | starting rating: 1440 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 293 | Kato, Akinori (1461) | Won 2-1 | +191459 |
| 2standard | 243 | Sakadani, Naoki (1501) | Lost 0-2 | -181441 |
| 3standard | 486 | Nakazawa, Yuki (1387) | Won 2-1 | +171458 |
| 4standard | 274 | Kimura, Kenta (1624) | Lost 1-2 | -151443 |
| 5standard | 664 | Shinagawa, Kazunari (1515) | Won 2-1 | +201463 |
| 6standard | 303 | Tsuji, Hayato (1516) | Won 2-0 | +191482 |
| 7standard | 315 | Hozumi, Yuji (1437) | Lost 1-2 | -191463 |
| 8standard | 376 | Toma, Hiroto (1718) | Lost 0-2 | -141449 |
| top | average opponent: 1520record: 4-4 | new rating: 1449 | ||
| Grand Prix Yokohama 2019 (modern) | starting rating: 1454 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 58 | Kurahara, Kenji (1500) | Lost 0-2 | -181436 |
| 2modern | 960 | Torii, Motonori (1583) | Lost 0-2 | -151421 |
| 3modern | 1165 | Amano, Seiichi (1398) | Won 2-0 | +181439 |
| 4modern | 902 | Oomura, Kounosuke (1480) | Lost 0-2 | -181421 |
| 5modern | 1064 | Tsushima, Toshiki (1465) | Won 2-0 | +191440 |
| top | average opponent: 1485record: 2-3 | new rating: 1440 | ||
| Grand Prix Kobe 2017 (modern) | starting rating: 1483 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 277 | Kawaguchi, Muneyoshi (1500) | Won 2-0 | +181501 |
| 2modern | 570 | Kashiwase, Kazuya (1591) | Won 2-1 | +201521 |
| 3modern | 496 | Takenouchi, Tetsuya (1715) | Lost 1-2 | -151506 |
| 4modern | 832 | Yu, Ching Kong (1579) | Lost 0-2 | -171489 |
| 5modern | 880 | Miyauchi, Kazutoshi (1487) | Lost 1-2 | -181471 |
| 6modern | 973 | Takashima, Daisuke (1480) | Lost 1-2 | -171454 |
| top | average opponent: 1559record: 2-4 | new rating: 1454 | ||
| Grand Prix Shizuoka 2017 (AER standard) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 145 | Yonezawa, Musashi (1730) | Lost 0-2 | -141486 |
| 2standard | 680 | Osada, Kousuke (1482) | Lost 1-2 | -181468 |
| 3standard | 1214 | Nakao, Yusuke (1464) | Lost 1-2 | -181450 |
| 4standard | 1238 | Lin, Juiche (1446) | Lost 1-2 | -181432 |
| 5standard | 1249 | Takezawa, Kouhei (1371) | Lost 0-2 | -191413 |
| 6standard | 1183 | Nishikawa, Satoshi (1344) | Won 2-0 | +171430 |
| 7standard | 1070 | Ashizawa, Yoshisato (1459) | Won 2-1 | +181448 |
| 8standard | 957 | Toride, Takumi (1446) | Won 2-0 | +181466 |
| 9standard | 797 | Kakihara, Shuichirou (1390) | Won 2-0 | +171483 |
| top | average opponent: 1459record: 4-5 | new rating: 1483 | ||