Rosa, William
Current rating: 1517
Record: 5-4
| Grand Prix Boston 2009 (M10 limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 236 | Chewning, Jeffrey J (1500) | Won 2-1 | +181518 |
| 2sealed | 159 | Shaler, Russell (1518) | Won 2-0 | +181536 |
| 3sealed | 48 | Li, Hai (1518) | Won 2-0 | +181554 |
| 4sealed | 78 | Domlack, Jeremy A (1539) | Lost 1-2 | -191535 |
| 5sealed | 57 | Prieto, Danilo (1474) | Lost 1-2 | -191516 |
| 6sealed | 149 | Wolloch, Adam (1551) | Won 2-1 | +191535 |
| 7sealed | 105 | Jacobson, Josh (1534) | Won 2-0 | +181553 |
| 8sealed | 62 | Huynh, Anthony (1557) | Lost 1-2 | -181535 |
| 9sealed | 73 | Batchelor, Justin T (1561) | Lost 0-2 | -181517 |
| average opponent: 1528record: 5-4 | new rating: 1517 | |||