Ishiwata, Kouichi
Current rating: 1633
Record: 49-38 (GP) / 1-5 (professional)
Grand Prix Chiba 2015Grand Prix Tokyo 2016Grand Prix Chiba 2016Grand Prix Chiba 2018Grand Prix Yokohama 2019Grand Prix Chiba 2019Grand Prix Nagoya 2020Regional Championships Aichi 2022Pro Tour PhyrexiaRegional Championships Yokohama 2023Regional Championships Chiba 2023Regional Championships Aichi 2023
| Regional Championships Aichi 2023 (pioneer) | starting rating: 1680 | |||
| round | table | opponent (rating) | result | Δrating |
| 1pioneer | 12 | Ooyama, Yuusuke (1591) | Won 2-0 | +161696 |
| 2pioneer | 42 | Shimamura, Kazushige (1568) | Lost 0-2 | -201676 |
| 3pioneer | 42 | ishikawa, akira (1502) | Lost 0-2 | -221654 |
| 4pioneer | 104 | Kohara, Soichiro (1438) | Lost 0-2 | -211633 |
| top | average opponent: 1525record: 1-3 | new rating: 1633 | ||
| Regional Championships Chiba 2023 (pioneer) | starting rating: 1707 | |||
| round | table | opponent (rating) | result | Δrating |
| 1pioneer | 8 | tanimura, yuma (1477) | Won 2-1 | +141721 |
| 2pioneer | 2 | Kubota, Kei (1569) | Lost 1-2 | -211700 |
| 3pioneer | 33 | Sasao, Yusuke (1667) | Lost 1-2 | -181682 |
| 4pioneer | 67 | Yamaguchi, Koutarou (1507) | Won 2-1 | +141696 |
| 5pioneer | 45 | Akaike, Yo (1760) | Lost 0-2 | -161680 |
| top | average opponent: 1596record: 2-3 | new rating: 1680 | ||
| Regional Championships Yokohama 2023 (ONE standard) | starting rating: 1626 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 63 | Hashimoto, Satoshi (1473) | Lost 0-2 | -211605 |
| 2standard | 51 | Uzuki, Yushi (1567) | Won 2-0 | +171622 |
| 3standard | 33 | Hishida, Akinori (1431) | Won 2-0 | +151637 |
| 4standard | 24 | Matsumoto, Tomohiro (1577) | Won 2-0 | +171654 |
| 5standard | 9 | Horiuchi, Makoto (1839) | Won 2-0 | +211675 |
| 6standard | 12 | Fujiwara, Mizuki (1638) | Won 2-1 | +171692 |
| 7standard | 8 | Segou, Kenji (1916) | Lost 0-2 | -141678 |
| 8standard | 11 | Masuda, Masahito (1794) | Lost 0-2 | -161662 |
| 9standard | 18 | Takahashi, Jun (1656) | Won 2-1 | +181680 |
| 10standard | 15 | Kong, Sangjoon (1624) | Won 2-1 | +171697 |
| 11standard | 9 | Masukado, Kenta (2042) | Lost 1-2 | -121685 |
| 12standard | 14 | Noine, Kazuhiro (1886) | Won 2-0 | +221707 |
| top | average opponent: 1704record: 8-4 | new rating: 1707 | ||
| Pro Tour Phyrexia (pioneer) | starting rating: 1675 | |||
| round | table | opponent (rating) | result | Δrating |
| 1draft | 71 | Castro, Miguel (2038) | Lost 0-2 | -121663 |
| 2draft | 83 | Kelly, Ryan (1665) | Lost 0-2 | -181645 |
| 3draft | 103 | Kassis, Eli (2040) | Lost 1-2 | -111634 |
| 4pioneer | 102 | Mackay, Richard (1701) | Lost 1-2 | -171617 |
| 5pioneer | 108 | Kowalski, Grzegorz (1849) | Won 2-0 | +231640 |
| 6pioneer | 102 | Bernat, Michael (1866) | Lost 0-2 | -141626 |
| top | average opponent: 1860record: 1-5 | new rating: 1626 | ||
| Regional Championships Aichi 2022 (pioneer) | starting rating: 1579 | |||
| round | table | opponent (rating) | result | Δrating |
| 1pioneer | 88 | Ikeda, Hidenari (1388) | Won 2-0 | +151594 |
| 2pioneer | 20 | Sakata, Naoya (1595) | Won 2-0 | +181612 |
| 3pioneer | 16 | Masukado, Kenta (2071) | Lost 1-2 | -101602 |
| 4pioneer | 35 | Kong, Sangjoon (1544) | Won 2-0 | +171619 |
| 5pioneer | 27 | Honda, Rintaro (1848) | Lost 0-2 | -141605 |
| 6pioneer | 35 | Ushio, Atsushi (1713) | Won 2-0 | +201625 |
| 7pioneer | 19 | Umetsubo, Tomoya (1550) | Won 2-1 | +161641 |
| 8pioneer | 10 | Kiyofuji, Kazuya (1593) | Lost 1-2 | -191622 |
| 9pioneer | 18 | Kobayashi, Akira (1536) | Won 2-0 | +171639 |
| 10pioneer | 12 | Utsunomiya, Takumi (1989) | Won 2-1 | +241663 |
| 11pioneer | 12 | Kumagai, Riku (2077) | Lost 1-2 | -111652 |
| 12pioneer | 14 | Tsubouchi, Tomoya (1926) | Won 2-0 | +231675 |
| top | average opponent: 1736record: 8-4 | new rating: 1675 | ||
| Grand Prix Nagoya 2020 (pioneer) | starting rating: 1602 | |||
| round | table | opponent (rating) | result | Δrating |
| 3pioneer | 400 | Ohtsuki, Shinya (1367) | Won 2-0 | +141616 |
| 4pioneer | 77 | Okamoto, Katsuki (1723) | Lost 0-2 | -161600 |
| 5pioneer | 155 | Matsushima, Yuki (1465) | Lost 0-2 | -211579 |
| 6pioneer | 262 | Okano, Yukimasa (1585) | Won 2-1 | +181597 |
| 7pioneer | 346 | Hirasawa, Daisuke (1592) | Lost 1-2 | -181579 |
| top | average opponent: 1546record: 2-3 | new rating: 1579 | ||
| Grand Prix Chiba 2019 (M20 limited) | starting rating: 1636 | |||
| round | table | opponent (rating) | result | Δrating |
| 3sealed | 49 | Hoshina, Kohei (1410) | Lost 1-2 | -221614 |
| 4sealed | 579 | Nagao, Kengo (1938) | Lost 0-2 | -121602 |
| top | average opponent: 1674record: 0-2 | new rating: 1602 | ||
| Grand Prix Yokohama 2019 (modern) | starting rating: 1597 | |||
| round | table | opponent (rating) | result | Δrating |
| 2modern | 510 | Daizo, Motoe (1479) | Won 2-0 | +161613 |
| 3modern | 172 | Sun, Bolong (1472) | Won 2-0 | +161629 |
| 4modern | 192 | Okudaira, Takenatsu (1577) | Won 2-1 | +171646 |
| 5modern | 130 | Takaoka, Yusuke (1517) | Won 2-0 | +151661 |
| 6modern | 42 | Sato, Tatsuo (1503) | Won 2-0 | +151676 |
| 7modern | 8 | Takahashi, Yuta (1997) | Won 2-0 | +241700 |
| 8modern | 11 | Kobayashi, Takahito (1918) | Lost 0-2 | -141686 |
| 9modern | 61 | Takagi, Takayuki (1802) | Won 2-1 | +201706 |
| 10modern | 29 | Kondo, Shogo (1679) | Lost 1-2 | -181688 |
| 11modern | 28 | Tanahashi, Masayasu (1959) | Lost 1-2 | -141674 |
| 12modern | 118 | Ohashi, Gaku (1689) | Lost 0-2 | -171657 |
| 13modern | 141 | Taki, Yoshikazu (1530) | Lost 0-2 | -211636 |
| top | average opponent: 1677record: 7-5 | new rating: 1636 | ||
| Grand Prix Chiba 2018 (M19 limited) | starting rating: 1649 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 151 | Mori, Fumiya (1448) | Won 2-1 | +141663 |
| 2sealed | 107 | Ichikawa, Takayoshi (1674) | Lost 0-2 | -181645 |
| 3sealed | 752 | Ooi, Adrian (1513) | Won 2-0 | +161661 |
| 4sealed | 356 | Hatakeyama, Atsushi (1524) | Lost 1-2 | -211640 |
| 5sealed | 532 | Ishizeki, Masaki (1500) | Lost 0-2 | -201620 |
| 6sealed | 798 | Li, Youchen (1532) | Lost 0-2 | -201600 |
| 7sealed | 692 | Tutui, Rintaro (1462) | Won 2-0 | +161616 |
| 8sealed | 550 | Tan, Joshua (1587) | Lost 1-2 | -191597 |
| top | average opponent: 1530record: 3-5 | new rating: 1597 | ||
| Grand Prix Chiba 2016 (legacy) | starting rating: 1671 | |||
| round | table | opponent (rating) | result | Δrating |
| 3legacy | 575 | Oda, Katsumi (1428) | Lost 0-2 | -221649 |
| top | record: 0-1 | new rating: 1649 | ||
| Grand Prix Tokyo 2016 (SOI standard) | starting rating: 1674 | |||
| round | table | opponent (rating) | result | Δrating |
| 2standard | 406 | Seo, Noboru (1498) | Lost 0-2 | -211653 |
| 3standard | 815 | Kanno, Atsushi (1578) | Won 2-0 | +171670 |
| 4standard | 1051 | Yuuki, Yoshihiro (1517) | Won 2-1 | +151685 |
| 5standard | 368 | Kurashina, Go (1539) | Won 2-1 | +151700 |
| 6standard | 195 | Kawashima, Masashi (1571) | Won 2-0 | +161716 |
| 7standard | 173 | Nogawa, Hiroshi (1548) | Won 2-0 | +151731 |
| 8standard | 73 | Aryabhima, Rahman (1775) | Lost 1-2 | -171714 |
| 9standard | 163 | Sun, Bo (1923) | Lost 0-2 | -141700 |
| 10standard | 425 | Gutesa, David (1552) | Lost 0-2 | -211679 |
| 11standard | 406 | Chiang, Siu On (1484) | Won 2-0 | +141693 |
| 12standard | 368 | Nomura, Takeshi (1446) | Lost 0-2 | -221671 |
| top | average opponent: 1585record: 6-5 | new rating: 1671 | ||
| Grand Prix Chiba 2015 (MM2 limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 2140 | Masuda, Takumi (1500) | Won 2-1 | +181518 |
| 2sealed | 2051 | Morita, Tomoyuki (1553) | Won 2-0 | +191537 |
| 3sealed | 2016 | Mita, Ryoichi (1505) | Lost 1-2 | -191518 |
| 4sealed | 2119 | Murakami, Mikihisa (1482) | Won 2-0 | +171535 |
| 5sealed | 2140 | Chi, Hsiang Li (1464) | Won 2-1 | +171552 |
| 6sealed | 2051 | Inazawa, Ryo (1688) | Won 2-0 | +211573 |
| 7sealed | 2068 | Sano, Yuuki (1563) | Won 2-0 | +171590 |
| 8sealed | 2021 | Nakatani, Shinji (1736) | Won 2-1 | +211611 |
| 9sealed | 2006 | Kobayashi, Tatsuumi (1710) | Won 2-0 | +201631 |
| 10draft | 86 | Sekimoto, Kandai (1817) | Won 2-0 | +211652 |
| 11draft | 60 | Mishima, Wataru (1780) | Lost 0-2 | -151637 |
| 12draft | 142 | Mochizuki, Kouta (1685) | Won 2-1 | +181655 |
| 13draft | 34 | Tsurifune, Takashi (1676) | Lost 1-2 | -171638 |
| 14draft | 112 | Matsumoto, Shou (1697) | Won 2-1 | +191657 |
| 15draft | 19 | Satou, Akihiko (1635) | Won 2-0 | +171674 |
| top | average opponent: 1633record: 12-3 | new rating: 1674 | ||