Brewster, Mark
Current rating: 1436
| Grand Prix Pittsburgh 2015 (modern) | starting rating: 1489 | |||
| round | table | opponent (rating) | result | Δrating |
| 1modern | 518 | Eilertsen, Mark (1402) | Lost 0-2 | -191470 |
| 2modern | 944 | Wall, Shawn (1482) | Won 2-0 | +181488 |
| 3modern | 1045 | Rowe, Taylor (1544) | Lost 0-2 | -171471 |
| 4modern | 861 | Durso, Andrew (1478) | Lost 1-2 | -181453 |
| 5modern | 1125 | Etters, Tyler (1516) | Lost 0-2 | -171436 |
| top | average opponent: 1484record: 1-4 | new rating: 1436 | ||
| Grand Prix Chicago 2014 (JOU standard) | starting rating: 1503 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 246 | Colon, George (1500) | Won 2-1 | +181521 |
| 2standard | 99 | Herring, Garrett (1518) | Lost 1-2 | -181503 |
| 3standard | 238 | Britten, Matt (1678) | Lost 0-2 | -151488 |
| 4standard | 348 | Merrick, Greg (1483) | Won 2-1 | +181506 |
| 5standard | 331 | Jarvis, Aaron (1574) | Lost 0-0 | -171489 |
| top | average opponent: 1551record: 2-3 | new rating: 1489 | ||
| Grand Prix Cincinnati 2014 (BNG standard) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 599 | Webster, Matthew (1494) | Won 2-1 | +181518 |
| 2standard | 245 | Durham, Derek (1518) | Won 2-1 | +181536 |
| 3standard | 182 | Cheng, Jonathan (1649) | Lost 1-2 | -161520 |
| 4standard | 473 | Wiley, Jonathan (1517) | Won 2-0 | +181538 |
| 5standard | 281 | Fiduk, Francis (1536) | Lost 1-2 | -181520 |
| 6standard | 239 | Deng, Steven (1541) | Lost 0-2 | -181502 |
| 7standard | 447 | Martin, David (1518) | Won 2-0 | +191521 |
| 8standard | 289 | Minniear, Adam (1552) | Lost 1-2 | -181503 |
| top | average opponent: 1541record: 4-4 | new rating: 1503 | ||