Obata, Ken
Current rating: 1518
Record: 35-36-2
| Grand Prix Chiba 2019 (M20 limited) | starting rating: 1554 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 70 | Ikarashi, Satoru (1536) | Lost 1-2 | -181536 |
| 2sealed | 665 | Orihara, Jun (1604) | Won 2-1 | +191555 |
| 3sealed | 744 | Wu, Mingshuai (1605) | Lost 0-2 | -171538 |
| 4sealed | 992 | Okamoto, Leo (1483) | Won 2-0 | +171555 |
| 5sealed | 734 | Morishita, Mizuki (1758) | Lost 0-2 | -141541 |
| 6sealed | 703 | Mayumi, Tomohito (1482) | Lost 0-2 | -191522 |
| 7sealed | 651 | Ishii, Masashi (1459) | Won 2-0 | +171539 |
| 8sealed | 506 | Uchida, Tomoaki (1374) | Lost 0-2 | -211518 |
| top | average opponent: 1538record: 3-5 | new rating: 1518 | ||
| Grand Prix Chiba 2018 (M19 limited) | starting rating: 1514 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 754 | Kanda, Shigeru (1424) | Won 2-1 | +171531 |
| 2sealed | 523 | Ehara, Kouta (1674) | Won 2-1 | +201551 |
| 3sealed | 278 | Kojima, Yoshifumi (1477) | Won 2-1 | +171568 |
| 4sealed | 233 | Matsuda, Taku (1473) | Lost 1-2 | -201548 |
| 5sealed | 498 | Matsumoto, Tomohiro (1590) | Lost 0-2 | -171531 |
| 6sealed | 473 | Ito, Takahiro (1504) | Won 2-0 | +181549 |
| 7sealed | 495 | Hirokawa, Tatsuya 2023 (1535) | Lost 1-2 | -191530 |
| 8sealed | 452 | Tada, Mitsuhiro (1872) | Won 2-1 | +241554 |
| top | average opponent: 1568record: 5-3 | new rating: 1554 | ||
| Grand Prix Kyoto 2017 (HOU limited) | starting rating: 1473 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 626 | Tamura, Yuto (1680) | Lost 0-2 | -141459 |
| 2sealed | 802 | Mori, Yohei (1499) | Draw 1-1 | +11460 |
| 3sealed | 972 | Sumitomo, Yusuke (1494) | Won 2-0 | +181478 |
| 4sealed | 805 | Yasu, Ryotaro (1676) | Lost 0-2 | -141464 |
| 5sealed | 928 | Nakashima, Shinnosuke (1405) | Won 2-0 | +171481 |
| 6sealed | 737 | Li, Qing (1368) | Won 2-0 | +161497 |
| 7sealed | 552 | Neki, Haruyuki (1479) | Lost 1-2 | -191478 |
| 8sealed | 679 | Sagawa, Zen (1480) | Won 2-1 | +181496 |
| 9sealed | 513 | Taki, Mayumi (1494) | Won 2-1 | +181514 |
| top | average opponent: 1508record: 5-3-1 | new rating: 1514 | ||
| Grand Prix Shizuoka 2017 (AER standard) | starting rating: 1463 | |||
| round | table | opponent (rating) | result | Δrating |
| 2standard | 513 | Isurugi, Hideyuki (1625) | Won 2-0 | +211484 |
| 3standard | 332 | Taniguchi, Yuki (1468) | Lost 0-2 | -181466 |
| 4standard | 721 | Yamaguchi, Yu (1479) | Lost 0-2 | -181448 |
| 5standard | 818 | Wada, Yousuke (1657) | Lost 0-2 | -141434 |
| 6standard | 1022 | Nakano, Tatsuhito (1532) | Lost 1-2 | -171417 |
| 7standard | 1004 | Ueno, Masaki (1499) | Won 2-1 | +201437 |
| 8standard | 834 | Saitou, Ryo (1420) | Won 2-0 | +181455 |
| 9standard | 744 | Takada, Narumasa (1495) | Won 2-1 | +181473 |
| top | average opponent: 1522record: 4-4 | new rating: 1473 | ||
| Grand Prix Tokyo 2016 (SOI standard) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 300 | Satou, Ryouta (1500) | Lost 1-2 | -181482 |
| 2standard | 1199 | Amano, Takatoshi (1391) | Lost 1-2 | -201462 |
| 3standard | 1484 | Ishii, Masashi (1386) | Lost 1-2 | -191443 |
| 4standard | 1562 | Kamiya, Kazuhiro (1335) | Won 2-1 | +161459 |
| 5standard | 1390 | Ookata, Akihiro 0810 (1464) | Won 2-1 | +181477 |
| 6standard | 1175 | Shingo, Tanaka (1521) | Lost 0-2 | -171460 |
| 7standard | 1226 | Matsumoto, Naoya (1579) | Won 2-1 | +201480 |
| 8standard | 957 | Sagara, Shota (1483) | Lost 0-2 | -181462 |
| 9standard | 877 | Lin, Yi-Tung (1504) | Draw 1-1 | +11463 |
| top | average opponent: 1463record: 3-5-1 | new rating: 1463 | ||
| Grand Prix Nagoya 2016 (OGW limited) | starting rating: 1492 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 843 | Itou, Kenta (1498) | Won 2-1 | +181510 |
| 2sealed | 63 | Ohtsu, Minami (1404) | Won 2-0 | +161526 |
| 3sealed | 464 | Ikebata, Ryou (1637) | Lost 1-2 | -161510 |
| 4sealed | 785 | Yoshioka, Ichita (1619) | Won 2-0 | +201530 |
| 5sealed | 281 | Higuchi, Jun (1642) | Lost 0-2 | -161514 |
| 6sealed | 410 | Yamaguchi, Shouta (1626) | Lost 1-2 | -161498 |
| 7sealed | 705 | Arai, Takanori (1420) | Won 2-0 | +171515 |
| 8sealed | 568 | Kodama, Yuu (1506) | Won 2-0 | +171532 |
| 9sealed | 525 | Kamikawa, Yusuke (1557) | Won 2-1 | +191551 |
| 10draft | 334 | Nagao, Shunsuke (1566) | Lost 0-2 | -181533 |
| 11draft | 357 | Usiro, Naoki (1565) | Lost 1-2 | -171516 |
| 13draft | 203 | Ogawa, Yohei (1603) | Won 2-1 | +191535 |
| 14draft | 68 | Motegi, Koichi (1518) | Lost 0-2 | -181517 |
| 15draft | 113 | Yamada, Tsutomu (1569) | Lost 1-2 | -171500 |
| top | average opponent: 1552record: 7-7 | new rating: 1500 | ||
| Grand Prix Chiba 2015 (MM2 limited) | starting rating: 1504 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 2062 | Komori, Yuuya (1500) | Won 2-1 | +181522 |
| 2sealed | 2093 | Kakihara, Shuichirou (1517) | Won 2-0 | +181540 |
| 3sealed | 2106 | Kawate, Junpei (1598) | Lost 1-2 | -171523 |
| 4sealed | 2171 | Jiang, Norman (1519) | Won 2-0 | +181541 |
| 5sealed | 2100 | Suzuike, Fumiyasu (1777) | Lost 0-2 | -141527 |
| 6sealed | 2256 | Saegusa, Nobuyuki (1607) | Lost 1-2 | -161511 |
| 7sealed | 2236 | Shimazu, Yoshiki (1510) | Lost 0-2 | -181493 |
| 8sealed | 2187 | Otsuka, Atsushi (1480) | Lost 0-2 | -181475 |
| 9sealed | 2142 | Yang, Shao-fu (1430) | Won 2-1 | +171492 |
| top | average opponent: 1549record: 4-5 | new rating: 1492 | ||
| Grand Prix Shizuoka 2015 (KTK limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 979 | Hamada, Etsuo (1557) | Won 2-1 | +191519 |
| 2sealed | 604 | Yoshida, Akinobu (1608) | Lost 0-2 | -161503 |
| 3sealed | 917 | Kawamae, Toshiyuki (1400) | Won 2-0 | +161519 |
| 4sealed | 846 | Uchimura, Yoshihiro (1589) | Won 2-1 | +191538 |
| 5sealed | 705 | Maruyama, Yuichiro (1532) | Lost 0-2 | -181520 |
| 6sealed | 780 | Tay, Jun Hao (1756) | Lost 1-2 | -141506 |
| 7sealed | 874 | Murasawa, Yuuya (1504) | Won 2-1 | +181524 |
| 8sealed | 772 | Furujou, Takashi (1427) | Lost 1-2 | -201504 |
| top | average opponent: 1547record: 4-4 | new rating: 1504 | ||