Williamson, Sean
Current rating: 1518
Record: 7-6
| Grand Prix Oakland 2010 (extended) | starting rating: 1516 | |||
| round | table | opponent (rating) | result | Δrating |
| 1extended | 37 | Tang, Tony (1500) | Won 2-0 | +171533 |
| 2extended | 25 | Kreyche, Jordan H (1545) | Won 2-0 | +191552 |
| 3extended | 53 | Keeth, Christian (1708) | Won 2-0 | +211573 |
| 4extended | 2 | Gardiner, Grant (1553) | Lost 1-2 | -191554 |
| 5extended | 70 | Beare, Tom (1541) | Lost 0-2 | -181536 |
| 6extended | 184 | campos, danny (1519) | Lost 1-2 | -181518 |
| average opponent: 1561record: 3-3 | new rating: 1518 | |||
| Grand Prix Los Angeles 2009 (extended) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1extended | 81 | Santos, Mark (1464) | Lost 1-2 | -191481 |
| 2extended | 283 | Asher, Micheal (1482) | Lost 0-2 | -181463 |
| 3extended | 328 | Woods, Matt L (1431) | Won 2-0 | +181481 |
| 4extended | 323 | Bailey, Stephen (1482) | Won 2-0 | +181499 |
| 5extended | 310 | Morton, Robert D (1500) | Won 2-0 | +181517 |
| 6extended | 178 | Cordova, Andrew (1458) | Won 2-0 | +171534 |
| 7extended | 175 | Lin, Tony J (1535) | Lost 1-2 | -181516 |
| average opponent: 1479record: 4-3 | new rating: 1516 | |||