| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. A Kosten vs Kurajica |
 | 1-0 | 38 |
1980 |
Evening Standard Chess Congress | B81 Sicilian, Scheveningen, Keres Attack |
| 2. A Kosten vs A Kuligowski |
| 0-1 | 29 |
1981 |
Lewisham op | B96 Sicilian, Najdorf |
| 3. A Kosten vs Chandler |
| 0-1 | 40 |
1985 |
England | B63 Sicilian, Richter-Rauzer Attack |
| 4. A Kosten vs Psakhis |
| ½-½ | 47 |
1986 |
Minsk | B81 Sicilian, Scheveningen, Keres Attack |
| 5. A Kosten vs Psakhis |
| ½-½ | 43 |
1987 |
Jurmala | B23 Sicilian, Closed |
| 6. A Kosten vs Adorjan |
 | 0-1 | 62 |
1988 |
Vesterhavs, Esbjerg | B81 Sicilian, Scheveningen, Keres Attack |
| 7. A Kosten vs Suba |
| 1-0 | 62 |
1988 |
London Lloyds | B84 Sicilian, Scheveningen |
| 8. A Kosten vs Larsen |
 | 0-1 | 53 |
1988 |
Hastings 8899 | B56 Sicilian |
| 9. A Kosten vs Larsen |
| ½-½ | 35 |
1988 |
Esbjerg | B39 Sicilian, Accelerated Fianchetto, Breyer Variation |
| 10. A Kosten vs Adorjan |
| ½-½ | 19 |
1989 |
Altensteig | B82 Sicilian, Scheveningen |
| 11. A Kosten vs O Cvitan |
| ½-½ | 35 |
1989 |
EU-chT (Men) | B42 Sicilian, Kan |
| 12. A Kosten vs Shirov |
| ½-½ | 22 |
1989 |
Val Maubuee (France) | B23 Sicilian, Closed |
| 13. A Kosten vs Larsen |
| 1-0 | 41 |
1990 |
London WFW | B36 Sicilian, Accelerated Fianchetto |
| 14. A Kosten vs Chandler |
| ½-½ | 40 |
1990 |
London (England) | B33 Sicilian |
| 15. A Kosten vs G Andruet |
| ½-½ | 115 |
1990 |
Toulouse op | B82 Sicilian, Scheveningen |
| 16. A Kosten vs Chandler |
 | 0-1 | 35 |
1991 |
It (cat.13) | B33 Sicilian |
| 17. A Kosten vs K Spraggett |
| ½-½ | 49 |
1991 |
Torcy (France) | B82 Sicilian, Scheveningen |
| 18. A Kosten vs Kharlov |
| ½-½ | 42 |
1991 |
Torcy op-A | B30 Sicilian |
| 19. A Kosten vs Smirin |
| 0-1 | 54 |
1992 |
Tilburg rapid | B82 Sicilian, Scheveningen |
| 20. A Kosten vs D Marciano |
 | ½-½ | 12 |
2000 |
L'Etang Sale | B33 Sicilian |
| 21. A Kosten vs M Hennigan |
 | 1-0 | 32 |
2000 |
4NCL | B26 Sicilian, Closed, 6.Be3 |
| 22. A Kosten vs D Gormally |
| 1-0 | 48 |
2001 |
4NCL | B32 Sicilian |
| 23. A Kosten vs Krum Georgiev |
 | 1-0 | 25 |
2005 |
Saint Affrique Open | B96 Sicilian, Najdorf |
| 24. A Kosten vs Fressinet |
| ½-½ | 10 |
2005 |
French Championship | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 25. A Kosten vs M Senff |
| 1-0 | 40 |
2006 |
Marseille Chess Festival | B20 Sicilian |