Ptak, John
Current rating: 1523
Record: 13-12-1
| Grand Prix Cleveland 2019 (RNA limited) | starting rating: 1519 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 72 | Boyd, Dylan (1795) | Lost 0-2 | -131506 |
| 2sealed | 357 | Lochridge, Lorin (1482) | Draw 1-1 | 01506 |
| 3sealed | 497 | Kendall, Alexander (1489) | Won 2-1 | +171523 |
| 4sealed | 421 | Tan, Ray (1515) | Won 2-1 | +181541 |
| 5sealed | 286 | Fredrichsen, Drew (1520) | Lost 1-2 | -181523 |
| top | average opponent: 1560record: 2-2-1 | new rating: 1523 | ||
| Grand Prix Cleveland 2015 (FRF limited) | starting rating: 1498 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 100 | Warren, Edward 2 (1500) | Won 2-0 | +181516 |
| 2sealed | 151 | Richardson, Robert (1570) | Won 2-1 | +191535 |
| 3sealed | 38 | Passarelli, Hayden (1558) | Lost 1-2 | -171518 |
| 4sealed | 420 | Eaton, Jansen (1499) | Lost 0-2 | -191499 |
| 5sealed | 584 | Genzman, Thomas (1607) | Won 2-0 | +201519 |
| 6sealed | 333 | Bubie, Adrian (1539) | Won 2-0 | +191538 |
| 7sealed | 261 | Nyhart, Ken (1498) | Lost 0-2 | -191519 |
| top | average opponent: 1539record: 4-3 | new rating: 1519 | ||
| Grand Prix Cincinnati 2014 (BNG standard) | starting rating: 1479 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 355 | Gordon, Alec (1500) | Won 2-0 | +181497 |
| 2standard | 148 | Williams, Tom (1444) | Won 2-0 | +181515 |
| 3standard | 41 | Vanemon, Chadd (1454) | Lost 0-2 | -201495 |
| 4standard | 194 | Dempsey, Brandon (1557) | Lost 1-2 | -161479 |
| 5standard | 621 | Treacle, Ryan (1503) | Won 2-0 | +181497 |
| 6standard | 462 | Rhees, Jake (1522) | Won 2-1 | +181515 |
| 7standard | 161 | Ellis, Joshua (1568) | Lost 1-2 | -171498 |
| top | average opponent: 1507record: 4-3 | new rating: 1498 | ||
| Grand Prix Pittsburgh 2013 (GTC limited) | starting rating: 1517 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 227 | Wilson, Mike (1480) | Lost 0-2 | -191498 |
| 2sealed | 623 | Horner, Aaron (1431) | Lost 0-2 | -191479 |
| top | average opponent: 1455record: 0-2 | new rating: 1479 | ||
| Grand Prix Pittsburgh 2011 (M12 standard) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 21 | Bruno, Patrick (1500) | Won 2-0 | +181518 |
| 2standard | 201 | Kronenberger, Chris (1569) | Lost 0-2 | -171501 |
| 3standard | 298 | Lemmon, Ryan (1485) | Won 2-0 | +181519 |
| 4standard | 409 | Jordan, Andrew (1519) | Won 2-1 | +181537 |
| 5standard | 203 | Martin, Michael (1446) | Lost 0-2 | -201517 |
| top | average opponent: 1504record: 3-2 | new rating: 1517 | ||