| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. J Benjamin vs DeFirmian |
| ½-½ | 44 |
1987 |
1, Estes Park USA ch | E32 Nimzo-Indian, Classical |
| 2. Hort vs DeFirmian |
| ½-½ | 49 |
1989 |
Biel | E32 Nimzo-Indian, Classical |
| 3. Gulko vs DeFirmian |
| 1-0 | 31 |
1989 |
Long | E32 Nimzo-Indian, Classical |
| 4. N Jenson vs DeFirmian |
| 0-1 | 23 |
1993 |
It (open) | E32 Nimzo-Indian, Classical |
| 5. Dao Thien Hai vs DeFirmian |
| 0-1 | 41 |
1993 |
Tilburg (Netherlands) | E32 Nimzo-Indian, Classical |
| 6. E Klein vs DeFirmian |
| 0-1 | 31 |
1993 |
New York op (04) | E32 Nimzo-Indian, Classical |
| 7. B Finegold vs DeFirmian |
| 1-0 | 36 |
1994 |
It (open) | E32 Nimzo-Indian, Classical |
| 8. M Hoffmann vs DeFirmian |
| ½-½ | 22 |
1994 |
It (open) | E32 Nimzo-Indian, Classical |
| 9. Flear vs DeFirmian |
 | 0-1 | 64 |
1994 |
It (open) | E32 Nimzo-Indian, Classical |
| 10. Adianto vs DeFirmian |
| 0-1 | 37 |
1995 |
It (cat.15) | E32 Nimzo-Indian, Classical |
| 11. Sadler vs DeFirmian |
| ½-½ | 39 |
1995 |
It (cat.11) | E32 Nimzo-Indian, Classical |
| 12. L Schandorff vs DeFirmian |
| ½-½ | 63 |
1996 |
Copenhagen (Denmark) | E32 Nimzo-Indian, Classical |
| 13. I Sokolov vs DeFirmian |
| ½-½ | 23 |
1996 |
It (cat.13) | E32 Nimzo-Indian, Classical |
| 14. I Sokolov vs DeFirmian |
| 0-1 | 40 |
1998 |
VISA GP | E32 Nimzo-Indian, Classical |
| 15. R H Fyllingen vs DeFirmian |
| 0-1 | 37 |
1999 |
Troll Masters | E32 Nimzo-Indian, Classical |
| 16. K Hovmoller vs DeFirmian |
| 0-1 | 56 |
2001 |
Politiken Cup | E32 Nimzo-Indian, Classical |
| 17. T Hillarp Persson vs DeFirmian |
| ½-½ | 43 |
2004 |
12th Sigeman & Co Chess Tournament | E32 Nimzo-Indian, Classical |
| 18. Goldin vs DeFirmian |
| 1-0 | 40 |
2006 |
US Championship 2006 | E32 Nimzo-Indian, Classical |