Prather, John
Current rating: 1468
| Grand Prix Portland 2016 (EMN standard) | starting rating: 1504 | |||
| round | table | opponent (rating) | result | Δrating |
| 1standard | 590 | Davis, Peter (1603) | Lost 0-2 | -171487 |
| 2standard | 540 | Ramos, Will (1481) | Lost 0-2 | -181469 |
| 3standard | 714 | Mason, Aiden (1462) | Won 2-0 | +181487 |
| 4standard | 736 | Allen, Timothy (1447) | Lost 0-2 | -191468 |
| top | average opponent: 1498record: 1-3 | new rating: 1468 | ||
| Grand Prix Portland 2010 (M11 limited) | starting rating: 1518 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 380 | McCombs, Leigh D (1500) | Won 2-0 | +181536 |
| 2sealed | 73 | Talim, Gary (1764) | Lost 1-2 | -141522 |
| 3sealed | 338 | Pickett, Alastair (1500) | Lost 0-2 | -181504 |
| top | average opponent: 1588record: 1-2 | new rating: 1504 | ||
| Grand Prix Seattle 2005 (extended) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1extended | 35 | Kreitzman, Daniel (1500) | Won 2-1 | +181518 |
| 2extended | 69 | Carlman, Cody (1500) | Lost 1-2 | -181500 |
| 3extended | 97 | Bundy, Dylan (1500) | Won 2-1 | +181518 |
| 4extended | 114 | Margate, Pedro (1518) | Lost 1-2 | -181500 |
| 5extended | 129 | Boychuk, Brady (1500) | Won 2-0 | +181518 |
| 6extended | 105 | Hendricks, John (1539) | Won 2-0 | +181536 |
| 7extended | 42 | Miller, Colin (1540) | Lost 1-2 | -181518 |
| top | average opponent: 1514record: 4-3 | new rating: 1518 | ||