| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. DeFirmian vs D Glueck |
| 1-0 | 50 |
1983 |
Pasadena (USA) | C19 French, Winawer, Advance |
| 2. DeFirmian vs J L Watson |
| 0-1 | 27 |
1984 |
Ch USA | C19 French, Winawer, Advance |
| 3. DeFirmian vs R Henley |
| ½-½ | 57 |
1984 |
Ch USA | C19 French, Winawer, Advance |
| 4. DeFirmian vs A Chernin |
 | 1-0 | 43 |
1985 |
Izt | C19 French, Winawer, Advance |
| 5. DeFirmian vs G Garcia |
| ½-½ | 40 |
1986 |
Olympiad | C19 French, Winawer, Advance |
| 6. DeFirmian vs G Rey |
| 1-0 | 45 |
1987 |
Ch USA | C19 French, Winawer, Advance |
| 7. DeFirmian vs D Edelman |
| 1-0 | 32 |
1988 |
It (open) | C19 French, Winawer, Advance |
| 8. DeFirmian vs R Reyes |
| 1-0 | 38 |
1988 |
It (open) | C19 French, Winawer, Advance |
| 9. DeFirmian vs G Garcia Gonzales |
| 0-1 | 30 |
1988 |
It (open) | C19 French, Winawer, Advance |
| 10. DeFirmian vs I Rogers |
| 1-0 | 75 |
1989 |
Cup World (open) | C19 French, Winawer, Advance |
| 11. DeFirmian vs Hebert |
 | 1-0 | 23 |
1989 |
San Mateo (USA) | C19 French, Winawer, Advance |
| 12. DeFirmian vs P Nikolic |
| ½-½ | 61 |
1990 |
Cup World (select) | C19 French, Winawer, Advance |
| 13. DeFirmian vs A Akopian |
| 0-1 | 51 |
1993 |
It (open) | C19 French, Winawer, Advance |
| 14. DeFirmian vs Remlinger |
| 1-0 | 46 |
1994 |
USA | C19 French, Winawer, Advance |
| 15. DeFirmian vs Gulko |
| 1-0 | 62 |
1995 |
It (cat.13) | C19 French, Winawer, Advance |
| 16. DeFirmian vs Hertneck |
| ½-½ | 42 |
1999 |
Bundesliga 9900 | C19 French, Winawer, Advance |
| 17. DeFirmian vs Gulko |
| ½-½ | 17 |
2001 |
Sigeman & Co | C19 French, Winawer, Advance |
| 18. DeFirmian vs Y Shulman |
| ½-½ | 29 |
2002 |
Imre Konig Mem | C19 French, Winawer, Advance |
| 19. DeFirmian vs P Cech |
| 1-0 | 43 |
2005 |
Politiken Cup | C19 French, Winawer, Advance |
| 20. DeFirmian vs I Ibragimov |
| ½-½ | 37 |
2005 |
Marshall Chess Club Championship | C19 French, Winawer, Advance |
| 21. DeFirmian vs M Antonsen |
| ½-½ | 44 |
2006 |
Politiken Cup | C19 French, Winawer, Advance |