Dumbelton, Jon
Current rating: 1575
Record: 12-8
| Grand Prix Sacramento 2018 (M19 limited) | starting rating: 1576 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 164 | Bischofberger, Lucas (1500) | Lost 0-2 | -201556 |
| 2sealed | 481 | Skrypov, Igor (1525) | Won 2-0 | +181574 |
| 3sealed | 457 | Hunt, Leighann (1671) | Won 2-0 | +201594 |
| 4sealed | 284 | Beltran, Matthew (1633) | Won 2-0 | +181612 |
| 5sealed | 167 | Mendoza, Rex (1579) | Lost 1-2 | -181594 |
| 6sealed | 263 | Robinson, Eli (1559) | Lost 0-2 | -191575 |
| average opponent: 1578record: 3-3 | new rating: 1575 | |||
| Grand Prix Sacramento 2014 (THS limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 327 | Hatfield, Michael (1500) | Won 2-1 | +181518 |
| 2sealed | 111 | Salveson, Eric G (1509) | Won 2-0 | +181536 |
| 3sealed | 20 | Li, Norman (1536) | Won 2-0 | +181554 |
| 4sealed | 56 | Baker, Nick (1397) | Won 2-0 | +151569 |
| 5sealed | 35 | Bozsik, Ryan (1519) | Won 2-0 | +171586 |
| 6sealed | 12 | Cribbs, Ryan (1841) | Lost 0-2 | -131573 |
| 7sealed | 20 | Bradley, Nick (1570) | Won 2-0 | +181591 |
| 8sealed | 31 | Smyth, Jason (1536) | Lost 0-2 | -191572 |
| 9sealed | 79 | Patrick, Douglas (1585) | Won 2-1 | +181590 |
| 10draft | 79 | Tabuga, Carl (1597) | Lost 0-2 | -181572 |
| 11draft | 32 | Brunson, Damyan (1581) | Won 2-0 | +181590 |
| 12draft | 37 | Obejas, Ammi (1695) | Lost 0-2 | -161574 |
| 13draft | 85 | Escobar, Nick (1651) | Won 2-1 | +191593 |
| 14draft | 12 | Hull, Ben (1609) | Lost 1-2 | -171576 |
| average opponent: 1580record: 9-5 | new rating: 1576 | |||