Marek, John
Current rating: 1466
| Grand Prix Minneapolis 2019 (modern) | starting rating: 1505 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 182 | Ehlers, Micah (1434) | Won 2-0 | +171522 |
| 2modern | 115 | Melby, Kristopher (1465) | Won 2-1 | +171539 |
| 3modern | 98 | Kramer, Kevan (1521) | Lost 1-2 | -191520 |
| 4modern | 215 | Jablonski, Alexander (1524) | Lost 1-2 | -171503 |
| 5modern | 327 | Panitz, Leah (1505) | Lost 1-2 | -181485 |
| 6modern | 304 | Bortz, Chad (1442) | Lost 1-2 | -191466 |
| top | average opponent: 1482record: 2-4 | new rating: 1466 | ||
| Grand Prix Minneapolis 2017 (HOU standard) | starting rating: 1497 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 287 | Beck, Austin (1500) | Won 2-1 | +191516 |
| 2standard | 236 | Preeshl, Tony (1644) | Won 2-0 | +201536 |
| 3standard | 10 | Berge, Ian (1534) | Won 2-0 | +181554 |
| 4standard | 42 | Griffin, Jeb (1575) | Lost 0-2 | -181536 |
| 5standard | 120 | Dasher, Ethan (1601) | Lost 0-2 | -171519 |
| 6standard | 232 | Beldon, Omar (1726) | Lost 0-2 | -141505 |
| top | average opponent: 1597record: 3-3 | new rating: 1505 | ||
| Grand Prix Minneapolis 2016 (SOI standard) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 158 | LaPlant, Parker (1415) | Won 2-0 | +161516 |
| 2standard | 173 | Hunter, J.R. (1462) | Lost 0-2 | -191497 |
| top | average opponent: 1438record: 1-1 | new rating: 1497 | ||