Iwanaga, Kohei
Current rating: 1341
Record: 21-32-1
| Grand Prix Yokohama 2019 (modern) | starting rating: 1369 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 225 | Arai, Tomoki (1450) | Lost 0-2 | -171352 |
| 2modern | 852 | Fumimoto, Kento (1482) | Lost 1-2 | -161336 |
| 3modern | 1197 | Tsuchiya, Yoshihiro (1361) | Lost 0-2 | -171319 |
| 4modern | 1139 | Nishioka, Daichi (1339) | Won 2-0 | +181337 |
| 5modern | 972 | Gao, Junmin (1423) | Lost 0-2 | -161321 |
| 6modern | 962 | Matsushima, Naoto (1441) | Won 2-0 | +201341 |
| top | average opponent: 1416record: 2-4 | new rating: 1341 | ||
| Grand Prix Shizuoka 2017 (AER standard) | starting rating: 1411 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 600 | Fujikura, Akinori (1568) | Lost 1-2 | -151396 |
| 2standard | 624 | U, Kashin (1607) | Won 2-1 | +211417 |
| 3standard | 1036 | Deguchi, Takahiro (1377) | Lost 1-2 | -181399 |
| 4standard | 996 | Nagasato, Kotaro (1479) | Lost 0-2 | -171382 |
| 5standard | 1223 | Fujita, Osamu (1637) | Lost 1-2 | -131369 |
| top | average opponent: 1534record: 1-4 | new rating: 1369 | ||
| Grand Prix Tokyo 2016 (SOI standard) | starting rating: 1459 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 173 | Isigaki, Nobuyuki (1450) | Won 2-1 | +181477 |
| 2standard | 317 | Anzai, Yuusuke (1615) | Lost 1-2 | -161461 |
| 3standard | 885 | Matsui, Yasuo (1552) | Lost 0-2 | -161445 |
| 4standard | 1504 | Hidefumi, Komino (1480) | Lost 1-2 | -171428 |
| 5standard | 1490 | Takahashi, Akira (Setagaya) (1468) | Lost 0-2 | -181410 |
| 6standard | 1380 | Ito, Tetsuya (1369) | Won 2-0 | +181428 |
| 7standard | 1194 | Hisamoto, Takashi (1485) | Lost 0-2 | -171411 |
| top | average opponent: 1488record: 2-5 | new rating: 1411 | ||
| Grand Prix Nagoya 2016 (OGW limited) | starting rating: 1515 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 143 | Konuma, Takanori (1500) | Lost 1-2 | -181497 |
| 2sealed | 721 | Okura, Yuji (1428) | Lost 0-2 | -201477 |
| 3sealed | 1153 | Sekido, Takashi (1464) | Lost 0-2 | -181459 |
| top | average opponent: 1464record: 0-3 | new rating: 1459 | ||
| Grand Prix Chiba 2015 (MM2 limited) | starting rating: 1450 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 1027 | Tanaka, Koichiro (1433) | Won 2-1 | +181468 |
| 2sealed | 1189 | Taitou, Masahiko (1479) | Won 2-0 | +181486 |
| 3sealed | 844 | Ooyama, Naoki (1535) | Lost 1-2 | -171469 |
| 4sealed | 968 | Seki, Takayuki (1518) | Won 2-1 | +191488 |
| 5sealed | 880 | Iyanaga, Junya (1977) | Lost 1-2 | -101478 |
| 6sealed | 1023 | Kaido, Yoshiaki (1422) | Won 2-1 | +171495 |
| 7sealed | 1013 | Kasahara, Takuya (1547) | Won 2-1 | +191514 |
| 8sealed | 952 | Tanooka, Shingo (1555) | Won 2-1 | +191533 |
| 9sealed | 895 | Sakai, Sadaharu (1529) | Lost 1-2 | -181515 |
| top | average opponent: 1555record: 6-3 | new rating: 1515 | ||
| Grand Prix Shizuoka 2015 (KTK limited) | starting rating: 1505 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 649 | Ogawa, Takashi (1497) | Lost 1-2 | -181487 |
| 2sealed | 907 | Suzuki, Shouta (1482) | Lost 0-2 | -191468 |
| 3sealed | 1079 | Motegi, Koichi (1464) | Lost 1-2 | -181450 |
| top | average opponent: 1481record: 0-3 | new rating: 1450 | ||
| Grand Prix Nagoya 2014 (BNG limited) | starting rating: 1468 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 539 | Goto, Shunsuke (1500) | Lost 1-2 | -181450 |
| 2sealed | 753 | Mitsui, Hideo (1459) | Won 2-1 | +181468 |
| 3sealed | 774 | Tsuchida, Yuuki (1393) | Won 2-0 | +171485 |
| 4sealed | 652 | Lee, Nam Hyoung (1356) | Draw 1-1 | -21483 |
| 5sealed | 697 | Moriya, Daichi (1517) | Won 2-0 | +181501 |
| 6sealed | 624 | Saitou, Keiichirou (1684) | Lost 0-2 | -141487 |
| 7sealed | 685 | Kelterbaum, Richard (1492) | Won 2-1 | +181505 |
| top | average opponent: 1486record: 4-2-1 | new rating: 1505 | ||
| Grand Prix Shizuoka 2013 (THS standard) | starting rating: 1508 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 240 | Itou, Hirokazu (1474) | Lost 0-2 | -191489 |
| 2standard | 314 | Nagata, Kazuya (1482) | Lost 0-2 | -181471 |
| 3standard | 401 | Chuuganji, Yoshimi (1358) | Won 2-1 | +161487 |
| 4standard | 323 | Kondo, Masahiro (1500) | Won 2-1 | +181505 |
| 5standard | 285 | Furutani, Yamato (1503) | Lost 0-2 | -181487 |
| 6standard | 298 | Hoshino, Tomoyuki (1477) | Won 2-1 | +181505 |
| 7standard | 241 | Ihara, Akihiro (1420) | Lost 0-2 | -191486 |
| 8standard | 213 | Suga, Hiroki (1482) | Lost 0-2 | -181468 |
| top | average opponent: 1462record: 3-5 | new rating: 1468 | ||
| Grand Prix Yokohama 2013 (GTC limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 9 | Kawabata, Sho (1500) | Won 2-1 | +181518 |
| 2sealed | 267 | Umemoto, Ryouta (1480) | Won 2-0 | +171535 |
| 3sealed | 91 | Kasuga, Ryosuke (1564) | Lost 1-2 | -171518 |
| 4sealed | 198 | Meguro, Masahiko (1499) | Won 2-0 | +181536 |
| 5sealed | 194 | Park, Jun Young (1767) | Lost 1-2 | -141522 |
| 6sealed | 248 | Sakamoto, Sakito (1764) | Lost 1-2 | -141508 |
| top | average opponent: 1596record: 3-3 | new rating: 1508 | ||