Costa, Oscar
Current rating: 1640
Record: 14-7
| Grand Prix Bilbao 2005 (extended) | starting rating: 1535 | |||
| round | table | opponent (rating) | result | Δrating |
| 2extended | 52 | Reis, Pedro M (1678) | Won 2-1 | +211556 |
| 3extended | 34 | Labiano, Alex (1536) | Won 2-1 | +171573 |
| 4extended | 14 | Nassif, Gabriel (1891) | Lost 1-2 | -121561 |
| 5extended | 81 | Ragull, Guillem (1546) | Won 2-1 | +181579 |
| 6extended | 51 | Rodano, Orlando (1670) | Lost 0-2 | -171562 |
| 7extended | 47 | Kouombille, Samuel (1455) | Won 2-0 | +161578 |
| 8extended | 26 | Palomar, Ruben (1553) | Won 2-0 | +181596 |
| 9extended | 27 | Aspas Tarrazon, Alvaro (1510) | ID | 01596 |
| 10extended | 63 | Rodriguez, Juan Alberto (1565) | Won 2-1 | +171613 |
| 11extended | 38 | Loriente, Alberto (1677) | Lost 0-2 | -171596 |
| 12extended | 47 | Perez, Bastien (1782) | Won 2-0 | +221618 |
| 13extended | 29 | Chan, Tiago (1827) | Lost 0-2 | -141604 |
| 14extended | 38 | Rodriguez Frye, Karel (1628) | Won 2-1 | +181622 |
| 15extended | 32 | Kirstein, Ivan (1620) | Won 2-1 | +181640 |
| average opponent: 1638record: 9-4-1 | new rating: 1640 | |||
| Grand Prix Lisbon 2005 (BOK limited) | starting rating: 1500 | |||
| round | table | opponent (rating) | result | Δrating |
| 1sealed | 28 | Oliveira, Pedro 3372 (1500) | Won 2-0 | +181518 |
| 2sealed | 75 | Ramos, Miguel (1498) | Lost 0-2 | -181500 |
| 3sealed | 103 | Caixinha, Bruno (1500) | Won 2-0 | +181518 |
| 4sealed | 68 | Murillo, Carlos (1518) | Won 2-1 | +181536 |
| 5sealed | 44 | Munoz Mena, Alberto (1535) | Lost 0-2 | -181518 |
| 6sealed | 112 | Santigo, Luis (1520) | Won 2-0 | +181536 |
| 7sealed | 71 | Santos, Helder (1552) | Won 2-1 | +181554 |
| 8sealed | 58 | Ortiz, Lucas (1504) | Lost 0-2 | -191535 |
| average opponent: 1516record: 5-3 | new rating: 1535 | |||