Piedra Diaz, Marvin
Current rating: 1488
Record: 2-3
| Grand Prix Costa Rica 2012 (M13 limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 35 | Aguilar, Melvin (1500) | Won 2-0 | +181518 |
| 3sealed | 19 | Rogachevsky, Victor (1640) | Won 2-1 | +201538 |
| 4sealed | 11 | DeTora, Melissa (1756) | Lost 0-2 | -141524 |
| 5sealed | 62 | Simon, Michael (1549) | Lost 0-2 | -171507 |
| 6sealed | 63 | Rivas, Ricardo J (1503) | Lost 1-2 | -191488 |
| average opponent: 1589record: 2-3 | new rating: 1488 | |||