Koizumi, Junichi
Current rating: 1488
Record: 6-7-5
| Grand Prix Chiba 2015 (MM2 limited) | starting rating: 1464 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 234 | Suewasa, Hiroya (1500) | Lost 1-2 | -171447 |
| 2sealed | 357 | Ouchi, Yoshitaka (1482) | Draw 1-1 | 01447 |
| 3sealed | 514 | Murakami, Yousuke (1482) | Won 2-1 | +191466 |
| 4sealed | 386 | Kanamura, Hiroyuki (1520) | Won 2-1 | +191485 |
| 5sealed | 260 | Ablack, Mukesh (1483) | Draw 1-1 | 01485 |
| 6sealed | 329 | Mitsuyasu, Hidetoshi (1501) | Lost 1-2 | -181467 |
| 7sealed | 291 | Murakami, Kazuya3837 (1746) | Lost 0-2 | -131454 |
| 8sealed | 231 | Kazuki, Rika (1320) | Won 2-1 | +161470 |
| 9sealed | 176 | Yamazaki, Takashi (1453) | Won 2-0 | +181488 |
| average opponent: 1499record: 4-3-2 | new rating: 1488 | |||
| Grand Prix Shizuoka 2015 (KTK limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 749 | Koike, Katsutoshi (1500) | Won 2-0 | +181518 |
| 2sealed | 821 | Yoshizawa, Kohei (1499) | Lost 1-2 | -181500 |
| 3sealed | 1039 | Kanaya, Hirosi (1501) | Draw 1-1 | 01500 |
| 4sealed | 934 | Matsuzaki, Ryuta (1500) | Lost 0-1 | -181482 |
| 5sealed | 1004 | Fujioka, Naoya (1501) | Lost 0-2 | -181464 |
| 6sealed | 965 | Mizuno, Yuya (1466) | Draw 1-1 | 01464 |
| 7sealed | 904 | Rutter, Jp (1464) | Lost 0-2 | -181446 |
| 8sealed | 852 | Muraki, Yuta (1446) | Draw 1-1 | 01446 |
| 9sealed | 808 | Ooyama, Hiroaki (1449) | Won 2-1 | +181464 |
| average opponent: 1481record: 2-4-3 | new rating: 1464 | |||