| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 1. M Burkett vs M Diesen |
 | 0-1 | 32 | 1971 | 72nd US Open | C17 French, Winawer, Advance |
| 2. P Biyiasas vs M Diesen |
| 1-0 | 60 | 1971 | 72nd US Open | C15 French, Winawer |
| 3. M Diesen vs A Saidy |
| 0-1 | 48 | 1972 | 73rd US Open | B98 Sicilian, Najdorf |
| 4. L Cohen vs M Diesen |
| 1-0 | 32 | 1972 | 73rd US Open | B03 Alekhine's Defense |
| 5. P Brandts vs M Diesen |
| 0-1 | 49 | 1972 | 73rd US Open | D97 Grunfeld, Russian |
| 6. M Diesen vs R Gruchacz |
| 0-1 | 32 | 1972 | 73rd US Open | B98 Sicilian, Najdorf |
| 7. W Burgar vs M Diesen |
| 0-1 | 55 | 1972 | 73rd US Open | B05 Alekhine's Defense, Modern |
| 8. M Diesen vs Nunn |
| 1-0 | 40 | 1973 | Hastings Challengers 1973/74 | B06 Robatsch |
| 9. M Diesen vs H Baumgartner |
| 1-0 | 35 | 1973 | International Junior Tournament | B52 Sicilian, Canal-Sokolsky (Rossolimo) Attack |
| 10. G Deleyn vs M Diesen |
| ½-½ | 63 | 1973 | International Junior Tournament | A28 English |
| 11. M Diesen vs Speelman |
| 0-1 | 30 | 1973 | International Junior Tournament | B52 Sicilian, Canal-Sokolsky (Rossolimo) Attack |
| 12. M Diesen vs K Grillitsch |
| 1-0 | 19 | 1973 | International Junior Tournament | B78 Sicilian, Dragon, Yugoslav Attack, 10.castle long |
| 13. P Ammann vs M Diesen |
| ½-½ | 36 | 1973 | International Junior Tournament | B77 Sicilian, Dragon, Yugoslav Attack |
| 14. C Hoi vs M Diesen |
| ½-½ | 28 | 1973 | International Junior Tournament | D97 Grunfeld, Russian |
| 15. M Diesen vs T Halasz |
| 1-0 | 11 | 1973 | International Junior Tournament | C72 Ruy Lopez, Modern Steinitz Defense, 5.O-O |
| 16. B Carlier vs M Diesen |
| 0-1 | 40 | 1973 | International Junior Tournament | B25 Sicilian, Closed |
| 17. C Ghysels vs M Diesen |
| 1-0 | 46 | 1973 | International Junior Tournament | B93 Sicilian, Najdorf, 6.f4 |
| 18. M Diesen vs G Ross |
| 1-0 | 21 | 1973 | 74th US Open | C00 French Defense |
| 19. F Bender vs M Diesen |
| 0-1 | 25 | 1973 | 74th US Open | B05 Alekhine's Defense, Modern |
| 20. M Diesen vs Browne |
| 0-1 | 44 | 1973 | 74th US Open | B93 Sicilian, Najdorf, 6.f4 |
| 21. M Pence vs M Diesen |
| 0-1 | 22 | 1973 | 74th US Open | A45 Queen's Pawn Game |
| 22. Lombardy vs M Diesen |
| ½-½ | 43 | 1973 | 74th US Open | A21 English |
| 23. E Vano vs M Diesen |
| 0-1 | 46 | 1973 | 74th US Open | B03 Alekhine's Defense |
| 24. M Diesen vs A Karklins |
| 0-1 | 53 | 1973 | 74th US Open | C96 Ruy Lopez, Closed |
| 25. S Gelbart vs M Diesen |
| 0-1 | 29 | 1973 | 74th US Open | B03 Alekhine's Defense |
Kibitzing
