| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. DeFirmian vs Hort |
| 0-1 | 42 |
1979 |
Lone Pine (USA) | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 2. DeFirmian vs Barlov |
| 0-1 | 35 |
1985 |
New York (USA) | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 3. DeFirmian vs Rohde |
| ½-½ | 54 |
1988 |
It (open) | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 4. DeFirmian vs R Stone |
| 1-0 | 36 |
1989 |
New York (USA) | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 5. DeFirmian vs Lautier |
 | 1-0 | 33 |
1990 |
It (cat.14) | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 6. DeFirmian vs G Franzoni |
| 1-0 | 47 |
1994 |
It (open) | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 7. DeFirmian vs V Zvjaginsev |
| 1-0 | 39 |
1994 |
It (open) | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 8. DeFirmian vs V Zvjaginsev |
| ½-½ | 21 |
1995 |
It (cat.15) | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 9. DeFirmian vs J Benjamin |
| ½-½ | 22 |
1995 |
03, ch-USA Modesto | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 10. DeFirmian vs S Giardelli |
| ½-½ | 26 |
1995 |
It (cat.11) | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 11. DeFirmian vs Kulaots |
| 1-0 | 74 |
1996 |
Copenhagen (Denmark) | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 12. DeFirmian vs J Benjamin |
| ½-½ | 16 |
1996 |
03, CITS New York USA | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 13. DeFirmian vs N Borge |
| 1-0 | 22 |
1999 |
Troll Masters | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 14. DeFirmian vs Fedorowicz |
| ½-½ | 20 |
2000 |
ch-USA | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 15. DeFirmian vs E Mortensen |
| ½-½ | 49 |
2001 |
Politiken Cup | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 16. DeFirmian vs Oral |
| 1-0 | 33 |
2003 |
Greenland Open | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 17. DeFirmian vs S Bercys |
| 1-0 | 32 |
2005 |
Marshall Chess Club Championship | B47 Sicilian, Taimanov (Bastrikov) Variation |
