Williamson, Mason
Current rating: 1553
Record: 24-24
| Grand Prix Atlanta 2017 (XLN standard) | starting rating: 1527 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 445 | Peretz, Michael (1749) | Won 2-1 | +221549 |
| 2standard | 243 | Zuelke, Christian (1496) | Won 2-0 | +171566 |
| 3standard | 280 | Matteson, Joshua (1539) | Lost 1-2 | -181548 |
| 4standard | 266 | Bozek, James (1432) | Won 2-1 | +161564 |
| 5standard | 124 | Napier, Cody (1719) | Won 2-1 | +211585 |
| 6standard | 122 | Wagner, Evan (1593) | Lost 1-2 | -181567 |
| 7standard | 225 | Rosum, Jonathan (1716) | Lost 0-2 | -161551 |
| 8standard | 294 | Parker, Lindsey (1520) | Won 2-0 | +181569 |
| 9standard | 223 | Schroeder, Max (1673) | Lost 0-2 | -161553 |
| top | average opponent: 1604record: 5-4 | new rating: 1553 | ||
| Grand Prix Washington DC 2017 (HOU standard) | starting rating: 1470 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 288 | Ertel, Daniel (1500) | Won 2-1 | +191489 |
| 2standard | 150 | Walters, Steven (1542) | Won 2-0 | +191508 |
| 3standard | 170 | Housman, Myles (1680) | Lost 1-2 | -151493 |
| 4standard | 310 | Haas, William (1708) | Lost 1-2 | -141479 |
| 5standard | 546 | Haussmann, Phil (1661) | Lost 1-2 | -151464 |
| 6standard | 616 | Kirk, Mitchell (1330) | Won 2-1 | +151479 |
| 7standard | 502 | Paugh, Jacob (1500) | Won 2-1 | +191498 |
| 8standard | 282 | Ciafardoni, Nick (1462) | Won 2-1 | +171515 |
| 9standard | 303 | Li, David (1630) | Won 2-1 | +201535 |
| 10standard | 184 | Jeffries, Richard (1559) | Won 2-0 | +191554 |
| 11standard | 99 | Komer, Jack (1582) | Won 2-0 | +181572 |
| 12standard | 59 | Koppier, Benjamin (1648) | Lost 1-2 | -161556 |
| 13standard | 114 | Graves, Robert (1879) | Lost 1-2 | -131543 |
| 14standard | 144 | Szylman, Dariusz (1656) | Lost 1-2 | -161527 |
| top | average opponent: 1596record: 8-6 | new rating: 1527 | ||
| Grand Prix Richmond 2017 (AKH limited) | starting rating: 1479 | |||
| round | table | opponent (rating) | result | Δrating |
| 2sealed | 141 | Walters, Cody (1520) | Lost 0-2 | -171462 |
| 3sealed | 637 | Lau, Kevin (1441) | Won 2-1 | +171479 |
| 4sealed | 389 | Wright, Matthew (1539) | Won 2-0 | +191498 |
| 5sealed | 213 | Dutton, Troy (1525) | Won 2-0 | +191517 |
| 6sealed | 179 | Floch, Ivan (2111) | Lost 0-2 | -91508 |
| 7sealed | 169 | Simmons, Aaron (1610) | Lost 0-2 | -161492 |
| 8sealed | 396 | Maine, Andrew (1692) | Won 2-0 | +221514 |
| 9sealed | 328 | Baker, Timothy (1561) | Won 2-0 | +191533 |
| 10draft | 749 | Asbach, John (1796) | Lost 0-2 | -141519 |
| 11draft | 645 | Freas, Gerald (1721) | Lost 0-2 | -141505 |
| 13draft | 770 | Tardif, David (1469) | Lost 0-2 | -191486 |
| 14draft | 735 | Milliken, Joshua (1581) | Lost 0-2 | -161470 |
| top | average opponent: 1631record: 5-7 | new rating: 1470 | ||
| Grand Prix Charlotte 2016 (modern) | starting rating: 1517 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 354 | Soto, Dustin (1500) | Lost 0-2 | -191498 |
| 2modern | 876 | Thomason, Robert (1482) | Won 2-1 | +181516 |
| 3modern | 866 | Bright, Nicholas (1502) | Lost 1-2 | -181498 |
| 4modern | 982 | Bennett, Christopher (1436) | Lost 0-2 | -191479 |
| top | average opponent: 1480record: 1-3 | new rating: 1479 | ||
| Grand Prix Charlotte 2015 (modern) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 1277 | Bailes, Blake (1471) | Lost 0-2 | -191481 |
| 2modern | 1586 | Thomas, Aaron M (1482) | Won 2-0 | +181499 |
| 3modern | 1536 | Tolar, Sandy (1483) | Lost 0-2 | -181481 |
| 4modern | 1611 | Braud, Chris (1422) | Won 2-0 | +171498 |
| 5modern | 1325 | Knorr, Nick (1500) | Won 2-1 | +181516 |
| 6modern | 1198 | Harris, Tim (1497) | Lost 0-2 | -181498 |
| 7modern | 1168 | Bodenbach, Ken (1494) | Won 2-0 | +181516 |
| 8modern | 923 | Long, Robert (1666) | Lost 0-2 | -161500 |
| 9modern | 836 | Nikla, Bryan (1408) | Won 2-0 | +171517 |
| top | average opponent: 1491record: 5-4 | new rating: 1517 | ||