Castro Fernandez, John
Current rating: 1517
Record: 3-2-1
| Grand Prix Costa Rica 2012 (M13 limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 134 | Rojas Salas, Jose Roberto (1500) | Draw 1-1 | 01500 |
| 3sealed | 126 | Salas Arroyo, Michael (1500) | Won 2-0 | +181518 |
| 4sealed | 104 | Salazar, Ivan Andres (1483) | Won 2-0 | +171535 |
| 5sealed | 74 | Reyes Chanto, Arianna (1536) | Lost 0-2 | -181517 |
| 6sealed | 100 | Rodriguez, Charles (1484) | Won 2-0 | +181535 |
| 7sealed | 73 | Campos, Ruben (1534) | Lost 0-1 | -181517 |
| average opponent: 1506record: 3-2-1 | new rating: 1517 | |||