Ishiduka, Katuya
Current rating: 1360
| Grand Prix Kobe 2017 (modern) | starting rating: 1400 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 460 | Yamamoto, Masayuki (1435) | Lost 0-2 | -171383 |
| 2modern | 950 | Itou, Isamu (1482) | Lost 1-2 | -161367 |
| 3modern | 1298 | Yamaha, Yasuhiro (1462) | Lost 1-2 | -171350 |
| 4modern | 1293 | Miyamoto, Naoki (1450) | Won 2-0 | +201370 |
| 5modern | 1099 | Okuyama, Sanshirou (1472) | Lost 1-2 | -161354 |
| 6modern | 1176 | Ootake, Syouki (1442) | Lost 1-2 | -161338 |
| 7modern | 1102 | Nakanishi, Kazuki (1412) | Won 2-1 | +191357 |
| 8modern | 944 | Hayano, Satosi (1447) | Lost 0-2 | -161341 |
| 9modern | 847 | Matsuda, Akio (1424) | Won 2-1 | +191360 |
| top | average opponent: 1447record: 3-6 | new rating: 1360 | ||
| Grand Prix Chiba 2016 (legacy) | starting rating: 1485 | |||
| round | table | opponent (rating) | result | Δrating |
| 1legacy | 649 | Otsuka, Atsushi (1516) | Lost 0-2 | -171468 |
| 2legacy | 702 | Nishimura, Masami (1489) | Lost 0-2 | -181450 |
| 3legacy | 1108 | Kobayashi, Hiroyuki (1672) | Lost 0-2 | -141436 |
| 4legacy | 1155 | Watanabe, Tomonari (1416) | Won 2-1 | +181454 |
| 5legacy | 1079 | Kannta, Hayashi (1463) | Lost 1-2 | -181436 |
| 6legacy | 1020 | Umeda, Satoshi (1406) | Won 2-1 | +171453 |
| 7legacy | 950 | Shang, Shuwen (1417) | Lost 1-2 | -181435 |
| 8legacy | 867 | Sakakura, Katsuya (1477) | Lost 0-2 | -171418 |
| 9legacy | 758 | Sitkowski, Mario (1449) | Lost 0-2 | -181400 |
| top | average opponent: 1478record: 2-7 | new rating: 1400 | ||
| Grand Prix Chiba 2015 (MM2 limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 1100 | Sekine, Naoto (1680) | Lost 0-2 | -151485 |
| 2sealed | 1406 | Kashimoto, Gaku (1482) | Won 2-1 | +181503 |
| 3sealed | 1241 | Mizutani, Tomohiko (1503) | Lost 0-2 | -181485 |
| top | average opponent: 1555record: 1-2 | new rating: 1485 | ||