| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. DeFirmian vs M Todorovic |
| 1-0 | 60 |
1984 |
It (cat.8) | B17 Caro-Kann, Steinitz Variation |
| 2. DeFirmian vs Dlugy |
 | 0-1 | 36 |
1985 |
Ch USA | B17 Caro-Kann, Steinitz Variation |
| 3. DeFirmian vs Dlugy |
| ½-½ | 46 |
1985 |
Izt | B17 Caro-Kann, Steinitz Variation |
| 4. DeFirmian vs Hort |
| 1-0 | 40 |
1985 |
Izt | B17 Caro-Kann, Steinitz Variation |
| 5. DeFirmian vs Christiansen |
| 1-0 | 63 |
1987 |
Ch USA | B17 Caro-Kann, Steinitz Variation |
| 6. DeFirmian vs J Thinnsen |
| 1-0 | 28 |
1988 |
World | B17 Caro-Kann, Steinitz Variation |
| 7. DeFirmian vs Spiridonov |
| 1-0 | 32 |
1989 |
It (open) | B17 Caro-Kann, Steinitz Variation |
| 8. DeFirmian vs Adorjan |
| ½-½ | 18 |
1989 |
Luzern 48/(210) | B17 Caro-Kann, Steinitz Variation |
| 9. DeFirmian vs J M Hodgson |
| 1-0 | 62 |
1990 |
Match (team) | B17 Caro-Kann, Steinitz Variation |
| 10. DeFirmian vs Karpov |
| 0-1 | 32 |
1990 |
It (open) | B17 Caro-Kann, Steinitz Variation |
| 11. DeFirmian vs A Fernandes |
| ½-½ | 52 |
1993 |
New York op (05) | B17 Caro-Kann, Steinitz Variation |
| 12. DeFirmian vs H Olafsson |
| ½-½ | 26 |
1994 |
Akureyri (Iceland) | B17 Caro-Kann, Steinitz Variation |
| 13. DeFirmian vs Gulko |
| ½-½ | 43 |
1994 |
Key West, Florida | B17 Caro-Kann, Steinitz Variation |
| 14. DeFirmian vs Razuvaev |
| ½-½ | 15 |
1994 |
It (open) | B17 Caro-Kann, Steinitz Variation |
| 15. DeFirmian vs Yudasin |
| ½-½ | 15 |
1994 |
USA | B17 Caro-Kann, Steinitz Variation |
| 16. DeFirmian vs Gulko |
| ½-½ | 14 |
1995 |
Ch USA | B17 Caro-Kann, Steinitz Variation |
| 17. DeFirmian vs Gulko |
| 0-1 | 37 |
1996 |
ch-USA, Parsippany | B17 Caro-Kann, Steinitz Variation |
| 18. DeFirmian vs C Lakdawala |
| 1-0 | 64 |
1996 |
American Open | B17 Caro-Kann, Steinitz Variation |
| 19. DeFirmian vs E Tegshsuren |
| 1-0 | 61 |
2003 |
US Championships 2003 | B17 Caro-Kann, Steinitz Variation |
