Okubo, Katsuya
Current rating: 1470
| Grand Prix Okayama 2008 (ALA limited) | starting rating: 1484 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 308 | Maehata, Yasuhito (1688) | Lost 0-0 | -141470 |
| top | record: 0-1 | new rating: 1470 | ||
| Grand Prix Hiroshima 2006 (CSP limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 115 | Tsuchiya, Hideaki (1591) | Won 2-0 | +201520 |
| 2sealed | 48 | Shoji, Kenta (1543) | Lost 0-2 | -181502 |
| 3sealed | 140 | Mori, Takashi (1506) | Lost 1-2 | -181484 |
| top | average opponent: 1547record: 1-2 | new rating: 1484 | ||
| Grand Prix Kyoto 2000 (extended) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1extended | 41 | Morizane, Hitoshi (1500) | Lost 0-2 | -181482 |
| 2extended | 253 | Hashimoto, Kengo (1482) | Won 2-0 | +181500 |
| 3extended | 187 | Nakamura, Hideto (1500) | Won 2-0 | +181518 |
| 4extended | 138 | Saito, Yoshihide (1518) | Lost 1-2 | -181500 |
| 5extended | 239 | Kena, Tadashi (1499) | Won 2-0 | +181518 |
| 6extended | 112 | Fujita, Osamu (1528) | Lost 0-2 | -181500 |
| top | average opponent: 1504record: 3-3 | new rating: 1500 | ||