Boris Kostic
Last tournaments played
| Tournament | Date | Elo Avg. | Country |
| Zuerich Seniors | ??/??/1962 | 0 | Switzerland |
| Hoogovens | ??/??/1952 | 0 | Netherlands |
| YUG-ch 6th | ??/??/1951 | 0 | |
| YUG-ch 6th+ | ??/??/1951 | 0 |
Boris Kostic Opening Repertoire with White pieces
| ECO | Opening | Games |
| B12 | Caro-Kann defence | 9 games |
| D64 | Queen's Gambit Declined, Orthodox defence, Rubinstein attack (with Rc1) | 8 games |
| C56 | Two knights defence | 6 games |
| B26 | Sicilian, closed, 6.Be3 | 5 games |
Boris Kostic Opening Repertoire with Black pieces
| ECO | Opening | Games |
| C42 | Petrov's defence | 11 games |
| D02 | Queen's pawn game | 9 games |
| D09 | Queen's Gambit Declined, Albin counter-gambit, 5.g3 | 6 games |
| D38 | Queen's Gambit Declined, Ragozin variation | 6 games |


Switzerland
Netherlands