Petko Kostov
Last tournaments played
| Tournament | Date | Elo Avg. | Country |
| BUL-ch14 | 02/??/1960 | 0 | Bulgaria |
| BUL-ch | ??/??/1959 | 0 | Bulgaria |
Most Played Openings as White
| ECO | Opening | Games |
| B22 | Sicilian, Alapin's variation (2.c3) | 3 games |
| C02 | French, advance variation | 2 games |
| B23 | Sicilian, closed | 1 games |
| C27 | Vienna game | 1 games |
Most Played Openings as Black
| ECO | Opening | Games |
| C63 | Ruy Lopez, Schliemann defence | 2 games |
| E62 | King's Indian, fianchetto variation | 2 games |
| C67 | Ruy Lopez, Berlin defence, open variation | 2 games |
| C97 | Ruy Lopez, closed, Chigorin defence | 1 games |


Bulgaria