| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 1. Dolmatov vs J Koscielski |
| 1-0 | 32 | 1992 | Dortmund Open-A | B92 Sicilian, Najdorf, Opocensky Variation |
| 2. C Michalek vs J Koscielski |
| 1-0 | 39 | 1992 | Dortmund Open-A | A05 Reti Opening |
| 3. J Koscielski vs J Moeldner |
| 0-1 | 35 | 1992 | Dortmund Open-A | B07 Pirc |
| 4. P Hertel vs J Koscielski |
| 0-1 | 75 | 1992 | Dortmund Open-A | B86 Sicilian, Fischer-Sozin Attack |
| 5. H Namyslo vs J Koscielski |
| 1-0 | 30 | 1992 | Dortmund Open-A | B97 Sicilian, Najdorf |
| 6. J Koscielski vs G Voss |
| 1-0 | 17 | 1992 | Dortmund Open-A | C05 French, Tarrasch |
| 7. J Koscielski vs B Fritze |
| 1-0 | 36 | 1992 | Dortmund Open-A | B18 Caro-Kann, Classical |
| 8. D Bischof vs J Koscielski |
| 1-0 | 44 | 1992 | Dortmund Open-A | E69 King's Indian, Fianchetto, Classical Main line |
| 9. J Hoehn vs J Koscielski |
| 0-1 | 17 | 1992 | Dortmund Open-A | B90 Sicilian, Najdorf |
| 10. J Koscielski vs K Movsziszian |
| 0-1 | 28 | 1992 | Dortmund Open-A | B97 Sicilian, Najdorf |
| 11. J Koscielski vs K Lewandowska |
| 1-0 | 67 | 1993 | Katowice Fibak Open | B33 Sicilian |
| 12. J Koscielski vs O Nikolenko |
| 0-1 | 31 | 1993 | Katowice Fibak Open | C08 French, Tarrasch, Open, 4.ed ed |
| 13. J Pietrzak vs J Koscielski |
| 0-1 | 50 | 1993 | Katowice Fibak Open | A00 Uncommon Opening |
| 14. J Koscielski vs Y Nesterov |
| 0-1 | 35 | 1993 | Katowice Fibak Open | A42 Modern Defense, Averbakh System |
| 15. J Koscielski vs J Urban |
| 0-1 | 76 | 1993 | Katowice Fibak Open | B38 Sicilian, Accelerated Fianchetto, Maroczy Bind, 6.Be3 |
| 16. S Galdunts vs J Koscielski |
| 0-1 | 30 | 1996 | Sueder Sommer op | B23 Sicilian, Closed |
| 17. A Aleksandrov vs J Koscielski |
| ½-½ | 44 | 1999 | Sportland-NRW-Cup | E73 King's Indian |
| 18. J Koscielski vs M Kopylov |
| ½-½ | 20 | 1999 | Dortmund op-A | B05 Alekhine's Defense, Modern |
| 19. U Rogge vs J Koscielski |
| 0-1 | 56 | 1999 | Sueder Sommer Open | B93 Sicilian, Najdorf, 6.f4 |
| 20. J Koscielski vs S Zrinscak |
| 1-0 | 57 | 1999 | Sueder Sommer Open | C48 Four Knights |
| 21. K Bischoff vs J Koscielski |
| 1-0 | 45 | 1999 | Sueder Sommer Open | E80 King's Indian, Samisch Variation |
| 22. J Koscielski vs I Wiegel |
| 1-0 | 47 | 1999 | Sueder Sommer Open | B36 Sicilian, Accelerated Fianchetto |
| 23. D Saavedra vs J Koscielski |
| ½-½ | 68 | 1999 | Sueder Sommer Open | B20 Sicilian |
| 24. S Kishnev vs J Koscielski |
| 1-0 | 33 | 1999 | Sueder Sommer Open | B51 Sicilian, Canal-Sokolsky (Rossolimo) Attack |
| 25. J Koscielski vs M Mroczek |
| 1-0 | 38 | 1999 | Sueder Sommer Open | A07 King's Indian Attack |
Kibitzing
