Koga, Ryuji
Current rating: 1526
Record: 46-43-2
| Grand Prix Kyoto 2019 (RNA standard) | starting rating: 1591 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 539 | Kaiho, Yuta (1500) | Draw 1-1 | -21589 |
| 2standard | 511 | Fujiwara, Koichi (1442) | Lost 0-2 | -211568 |
| 3standard | 874 | Morita, Kazuki (1424) | Lost 0-2 | -201548 |
| 4standard | 937 | Seino, Kouhei (1464) | Won 2-0 | +161564 |
| 5standard | 807 | Shibata, Takeshi (1527) | Lost 0-2 | -191545 |
| 6standard | 742 | Katakuwa, Dai (1451) | Lost 0-2 | -191526 |
| top | average opponent: 1468record: 1-4-1 | new rating: 1526 | ||
| Grand Prix Shizuoka 2018 (standard) (GRN standard) | starting rating: 1611 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 575 | Matsubara, Akifumi (1519) | Won 2-0 | +171628 |
| 2standard | 495 | Ichikawa, Hideyuki (1546) | Lost 1-2 | -201608 |
| 3standard | 882 | Hagiya, Ginga (1505) | Lost 0-2 | -201588 |
| 4standard | 899 | Sato, Motohiko (1693) | Won 2-0 | +201608 |
| 5standard | 684 | Tamada, Ryoichi (1923) | Lost 1-2 | -121596 |
| 6standard | 795 | Atsuji, Makoto (1442) | Won 2-1 | +151611 |
| 7standard | 659 | Nakamura, Akiteru (1479) | Lost 0-2 | -201591 |
| top | average opponent: 1587record: 3-4 | new rating: 1591 | ||
| Grand Prix Chiba 2018 (M19 limited) | starting rating: 1626 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 390 | Fukushima, Yuuhei (1523) | Won 2-1 | +161642 |
| 2sealed | 60 | Mukai, Hiroaki (1446) | Lost 0-2 | -211621 |
| 3sealed | 956 | Tanaka, Kisuke (1392) | Won 2-0 | +141635 |
| 4sealed | 708 | Fujimura, Akinori (1478) | Lost 1-2 | -211614 |
| 5sealed | 880 | Yamamoto, Keiichi (1587) | Won 2-0 | +171631 |
| 6sealed | 654 | Sakurai, Ryota (1523) | Lost 1-2 | -201611 |
| top | average opponent: 1491record: 3-3 | new rating: 1611 | ||
| Grand Prix Hong Kong 2017 (XLN limited) | starting rating: 1637 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 101 | Loh, Chuan Han (1706) | Lost 1-2 | -171620 |
| 2sealed | 230 | Chan, Ming Kin (1570) | Lost 0-2 | -191601 |
| 3sealed | 315 | Tang, Alex (1468) | Won 2-0 | +161617 |
| 4sealed | 311 | Leong, Yongbo (1483) | Won 2-0 | +151632 |
| 5sealed | 246 | Liang, Mo (1626) | Lost 1-2 | -181614 |
| 6sealed | 253 | Ng, Meng Cheong (1682) | Won 2-1 | +191633 |
| 7sealed | 243 | Chandrindra, Phath (1460) | Won 2-0 | +151648 |
| 8sealed | 191 | Yuk, Kai Leung (1431) | Lost 1-2 | -221626 |
| top | average opponent: 1553record: 4-4 | new rating: 1626 | ||
| Grand Prix Kobe 2017 (modern) | starting rating: 1597 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 161 | Paul, Benjamin (1465) | Lost 1-2 | -201577 |
| 2modern | 805 | Uchida, Shogo (1481) | Won 2-0 | +161593 |
| 3modern | 994 | Hamaguchi, Masakuni (1718) | Won 2-1 | +211614 |
| 4modern | 605 | Ji, Zihao (1770) | Lost 1-2 | -161598 |
| 5modern | 810 | Okuhara, Yuuki (1606) | Won 2-1 | +191617 |
| 6modern | 590 | Nitta, Toshiya (1474) | Won 2-1 | +151632 |
| 7modern | 609 | Iwazaki, Yuuta (1705) | Won 2-0 | +191651 |
| 8modern | 315 | Matsuo, Shuto (1512) | Won 2-1 | +161667 |
| 9modern | 258 | Saitou, Ryuuga (1963) | Lost 1-2 | -131654 |
| 10modern | 315 | Kawahama, Yoshikazu (1777) | Won 2-0 | +201674 |
| 11modern | 235 | Nakao, Motohiko (1575) | Lost 0-2 | -201654 |
| 12modern | 314 | Furuta, Yusuke (1659) | Lost 0-2 | -171637 |
| top | average opponent: 1642record: 7-5 | new rating: 1637 | ||
| Grand Prix Taipei 2016 (SOI standard) | starting rating: 1529 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 1003 | Lin, Zen Wei (1496) | Lost 0-2 | -181511 |
| 2standard | 1006 | Li, Xiang (1512) | Won 2-1 | +181529 |
| 3standard | 1022 | Liu, Thomas (1481) | Won 2-0 | +171546 |
| 4standard | 1016 | Li, Sean (1764) | Won 2-1 | +221568 |
| 5standard | 1011 | Lee, Timothy (1534) | Won 1-0 | +171585 |
| 6standard | 1003 | Siao, G. Shung (1594) | Lost 1-2 | -181567 |
| 7standard | 1006 | Kawahara, Masanobu (1400) | Lost 1-2 | -211546 |
| 8standard | 1011 | Zhong, Jian Wei (1525) | Won 2-1 | +181564 |
| 9standard | 1007 | Chong, Edwin (1570) | Won 2-1 | +181582 |
| 10standard | 1007 | Chu, Huseh Lan (1584) | Won 2-1 | +181600 |
| 11standard | 1004 | Washida, Hiroshi (1553) | Draw 1-1 | -11599 |
| 12standard | 1003 | Fung, Chun Sing (1644) | Lost 1-2 | -171582 |
| 13standard | 1005 | Wong, Teck Shen Lucas (1539) | Lost 0-2 | -191563 |
| 14standard | 1007 | Yu, Weilong (1477) | Won 2-0 | +171580 |
| 15standard | 1003 | Shiau, Yuan-Shiung (1577) | Won 2-1 | +171597 |
| top | average opponent: 1550record: 9-5-1 | new rating: 1597 | ||
| Grand Prix Kobe 2015 (BFZ standard) | starting rating: 1498 | |||
| round | table | opponent (rating) | result | Δrating |
| 2standard | 266 | Takahashi, Koji (1420) | Won 2-1 | +171515 |
| 3standard | 526 | Gao, Tan (1727) | Won 2-1 | +221537 |
| 4standard | 202 | Sasaki, Yusuke (1640) | Lost 0-1 | -161521 |
| 5standard | 425 | Kawasaki, Keita (1912) | Lost 1-2 | -121509 |
| 6standard | 665 | Chiba, Takato (1526) | Won 2-1 | +191528 |
| 7standard | 458 | Sasabe, Yusuke (1596) | Won 2-0 | +191547 |
| 8standard | 325 | Yamagata, Hiroki (1557) | Lost 0-2 | -181529 |
| top | average opponent: 1626record: 4-3 | new rating: 1529 | ||
| Grand Prix Chiba 2015 (MM2 limited) | starting rating: 1478 | |||
| round | table | opponent (rating) | result | Δrating |
| 2sealed | 2161 | Obitsu, Youtarou (1506) | Lost 0-2 | -181460 |
| 3sealed | 2334 | Takiguchi, Itsuki (1501) | Lost 1-2 | -171443 |
| 4sealed | 2381 | Ihara, Akihiro (1353) | Won 2-0 | +171460 |
| 5sealed | 2279 | Morimura, Kenichi (1518) | Won 2-1 | +191479 |
| 6sealed | 2246 | Katou, Takeru (1490) | Won 2-0 | +181497 |
| 7sealed | 2159 | Suzuki, Takayoshi (1538) | Won 2-0 | +191516 |
| 8sealed | 2125 | Matuda, Amane (1558) | Lost 0-2 | -181498 |
| top | average opponent: 1495record: 4-3 | new rating: 1498 | ||
| Grand Prix Kyoto 2015 (legacy) | starting rating: 1495 | |||
| round | table | opponent (rating) | result | Δrating |
| 2legacy | 570 | Miyakawa, Toshihiro (1554) | Lost 0-2 | -171478 |
| 3legacy | 819 | Losh, Mason (1403) | Won 2-1 | +171495 |
| 4legacy | 798 | Kawaguchi, Tetsu (1480) | Lost 1-2 | -191476 |
| 5legacy | 727 | Tsukahara, Kazuto (1647) | Won 2-0 | +211497 |
| 6legacy | 724 | Kawakami, Teppei (1467) | Won 2-0 | +181515 |
| 7legacy | 598 | Miyazaki, Kensuke (1442) | Lost 1-2 | -191496 |
| 8legacy | 662 | Smallheer, Matthew (1517) | Lost 1-2 | -181478 |
| top | average opponent: 1501record: 3-4 | new rating: 1478 | ||
| Grand Prix Kobe 2014 (modern) | starting rating: 1477 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 36 | Kamimura, Yohei (1500) | Lost 1-2 | -181459 |
| 2modern | 369 | Nakae, Kazusi (1416) | Won 2-1 | +181477 |
| 3modern | 336 | Hatta, Tetsuya (1478) | Lost 1-2 | -181459 |
| 4modern | 461 | Okubo, Mai (1489) | Won 2-1 | +181477 |
| 5modern | 376 | Nitta, Shuuhei (1415) | Lost 0-2 | -191458 |
| 6modern | 436 | Niwa, Hotaka (1467) | Won 2-1 | +181476 |
| 7modern | 354 | Itou, Tadashi (1523) | Won 2-0 | +191495 |
| top | average opponent: 1470record: 4-3 | new rating: 1495 | ||
| Grand Prix Nagoya 2014 (BNG limited) | starting rating: 1498 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 654 | Takemura, Junta (1419) | Lost 0-2 | -191479 |
| 2sealed | 800 | Takahashi, Jun (1381) | Lost 1-2 | -201459 |
| 3sealed | 883 | Okamoto, Yuta (Tokyo) (1464) | Won 2-0 | +181477 |
| 4sealed | 851 | Ohata, Norio (1488) | Won 2-1 | +181495 |
| 5sealed | 789 | Kim, Taehyoung (1468) | Lost 0-2 | -181477 |
| top | average opponent: 1444record: 2-3 | new rating: 1477 | ||
| Grand Prix Shizuoka 2013 (THS standard) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 66 | Takahashi, Toshiyuki (1500) | Lost 1-2 | -181482 |
| 2standard | 264 | Mizuno, Takayuki (1481) | Lost 1-2 | -181464 |
| 3standard | 408 | Kawaguchi, Hiroshi (1472) | Won 2-1 | +181482 |
| 4standard | 358 | Ishimura, Kenji (1380) | Won 2-1 | +161498 |
| top | average opponent: 1458record: 2-2 | new rating: 1498 | ||