Sumida, Ken
Current rating: 1530
Record: 7-6
| Grand Prix Kitakyushu 2009 (ZEN limited) | starting rating: 1501 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 19 | Okauchi, Yuuta (1392) | Won 2-1 | +161517 |
| 2sealed | 25 | Moriya, Jun (1655) | Won 2-0 | +211538 |
| 3sealed | 34 | Baba, Youichi (1534) | Won 2-0 | +181556 |
| 4sealed | 46 | Shimizu, Naoki (1947) | Lost 1-2 | -121544 |
| 5sealed | 49 | Miyazono, Takeshi (1546) | Won 2-0 | +181562 |
| 6sealed | 34 | Shiraishi, Tomomi (1645) | Lost 0-2 | -161546 |
| 7sealed | 61 | Nakamura, Yusuke (1667) | Lost 0-2 | -161530 |
| average opponent: 1627record: 4-3 | new rating: 1530 | |||
| Grand Prix Okayama 2008 (ALA limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 254 | Sakata, Akinori (1500) | Won 0-0 | +181518 |
| 2sealed | 133 | Abe, Ken'Ichi (1487) | Won 2-0 | +171535 |
| 3sealed | 35 | Juumonji, Ryou (1617) | Lost 0-2 | -161519 |
| 4sealed | 101 | Yamauchi, Shou (1575) | Won 2-0 | +191538 |
| 5sealed | 74 | Yao, Shunsuke (1499) | Lost 1-2 | -191519 |
| 6sealed | 4 | Babasaki, Taro (1514) | Lost 0-2 | -181501 |
| average opponent: 1532record: 3-3 | new rating: 1501 | |||