Costello, Jay
Current rating: 1536
Record: 6-4
| Grand Prix Boston 2003 (LGN limited) | starting rating: 1538 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 163 | Hickey III, Raymond (1500) | Won 2-1 | +171555 |
| 2sealed | 123 | Beresford, John (1482) | Won 2-0 | +171572 |
| 3sealed | 26 | Fiorillo, John (1537) | Lost 1-2 | -191553 |
| 4sealed | 182 | Chin, Chris (1561) | Lost 0-2 | -171536 |
| average opponent: 1520record: 2-2 | new rating: 1536 | |||
| Grand Prix Boston 2001 (PLS limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 172 | Kuhn, Brian (1500) | Won 2-0 | +181518 |
| 2sealed | 99 | Graham, Isaac (1518) | Won 2-1 | +181536 |
| 3sealed | 12 | Tsoi, Man (1491) | Won 2-1 | +171553 |
| 4sealed | 57 | Pamphret, Mark (1554) | Won 2-1 | +181571 |
| 5sealed | 26 | Farkas, Benjamin (1723) | Lost 1-2 | -151556 |
| 6sealed | 28 | Robertsen, Christian (1565) | Lost 0-2 | -181538 |
| average opponent: 1558record: 4-2 | new rating: 1538 | |||