Kozak, Jan
Current rating: 1448
Record: 5-8
| Grand Prix Prague 2011 (NPH limited) | starting rating: 1484 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 520 | Zigo, Peter (1500) | Lost 0-2 | -181466 |
| 2sealed | 718 | Wintrich, Patrick (1412) | Lost 0-2 | -191447 |
| 3sealed | 746 | Renger, Michael (1465) | Won 2-0 | +191466 |
| 4sealed | 698 | Vermeiren, Yves (1496) | Lost 0-2 | -181448 |
| average opponent: 1468record: 1-3 | new rating: 1448 | |||
| Grand Prix Prague 2009 (M10 limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 114 | Mahdal, Oldrich (1500) | Lost 0-2 | -181482 |
| 2sealed | 279 | Bosselmann, Tobias (1636) | Lost 1-2 | -151467 |
| 3sealed | 305 | Kordovan, Daniel (1455) | Lost 0-2 | -181449 |
| 4sealed | 346 | Panocha, Radek (1446) | Won 2-0 | +181467 |
| 5sealed | 304 | Augustin, Marek (1462) | Won 2-1 | +171484 |
| 6sealed | 233 | Stehlik, Mirek (1482) | Won 2-0 | +181502 |
| 7sealed | 171 | Hajek, Tomas (1449) | Won 2-0 | +171519 |
| 8sealed | 137 | Ameeuw, Sebastien (1550) | Lost 0-2 | -171502 |
| 9sealed | 114 | Dyntar, Petr (1507) | Lost 1-2 | -181484 |
| average opponent: 1499record: 4-5 | new rating: 1484 | |||