Koszewski, Gustaw
Current rating: 1506
| Grand Prix Krakow 2019 (M20 limited) | starting rating: 1489 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 456 | Hajek, Piotr (1439) | Won 2-0 | +171506 |
| 2sealed | 409 | Gorbunov, Ivan (1539) | Lost 1-2 | -171489 |
| 3sealed | 347 | De Wit, Wiebe (1499) | Won 2-0 | +181507 |
| 4sealed | 205 | Szal, Bogumil (1499) | Lost 0-2 | -181489 |
| 5sealed | 294 | Toth, Ferenc (1396) | Won 2-0 | +161505 |
| 6sealed | 223 | Hybasek, Roman (1528) | Won 2-1 | +181523 |
| 7sealed | 306 | Oros, Bogdan (1536) | Lost 0-2 | -171506 |
| top | average opponent: 1491record: 4-3 | new rating: 1506 | ||
| Grand Prix Prague 2015 (ORI standard) | starting rating: 1498 | |||
| round | table | opponent (rating) | result | Δrating |
| 3standard | 130 | Heiss, Marvin (1724) | Lost 0-2 | -141484 |
| 4standard | 308 | Nagy, Szabolcs (1517) | Won 2-0 | +191503 |
| 5standard | 168 | Turkovic, Filip (1724) | Lost 0-2 | -141489 |
| 6standard | 273 | Amendola, Michele (1484) | Lost 1-2 | -181471 |
| 7standard | 406 | Bohuslav, Robert (1442) | Lost 1-2 | -191452 |
| 8standard | 390 | Valousek, Jiri (1480) | Won 2-1 | +191471 |
| 9standard | 280 | Schulz, Jan-Hendrik (1472) | Won 2-1 | +181489 |
| top | average opponent: 1549record: 3-4 | new rating: 1489 | ||
| Grand Prix Warsaw 2013 (M14 standard) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 16 | Radecki, Michal (1518) | Won 2-0 | +181518 |
| 2standard | 20 | Olak, Dominik (1471) | Won 2-0 | +171535 |
| 3standard | 49 | Habluetzel, Matthias (1542) | Won 2-0 | +191554 |
| 4standard | 139 | Scholtens, Desmond (1605) | Lost 0-2 | -171537 |
| 5standard | 200 | Bornelov, Susanne (1556) | Lost 0-2 | -181519 |
| 6standard | 218 | Olczak, Dariusz (1375) | Lost 1-2 | -211498 |
| top | average opponent: 1511record: 3-3 | new rating: 1498 | ||