| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. D Gillespie vs I Marks |
| 0-1 | 18 |
1986 |
corr | E69 King's Indian, Fianchetto, Classical Main line |
| 2. M Dyer vs I Marks |
| 0-1 | 39 |
1987 |
corr | A52 Budapest Gambit |
| 3. I Marks vs A Berlin |
 | 1-0 | 12 |
1990 |
W 067 | C15 French, Winawer |
| 4. I Marks vs J Moormann |
| ½-½ | 18 |
1990 |
W 067 | C56 Two Knights |
| 5. I Marks vs W Riemer |
| 0-1 | 22 |
1991 |
WT/M/GT/287 | B90 Sicilian, Najdorf |
| 6. V Ikonnikov vs I Marks |
| 1-0 | 27 |
2005 |
28th Ghent Open | B38 Sicilian, Accelerated Fianchetto, Maroczy Bind, 6.Be3 |
| 7. I Marks vs T Vasilevich |
| 0-1 | 37 |
2006 |
15th Monarch Assurance | B43 Sicilian, Kan, 5.Nc3 |
| 8. I Marks vs A Grant Kerr |
| ½-½ | 24 |
2007 |
Isle of Man International | A17 English |
| 9. M Yeo vs I Marks |
| ½-½ | 55 |
2007 |
Isle of Man International | B97 Sicilian, Najdorf |
| 10. A Szieberth vs I Marks |
| 1-0 | 61 |
2007 |
Isle of Man International | B82 Sicilian, Scheveningen |
| 11. I Marks vs J Bentley |
| 0-1 | 54 |
2007 |
Isle of Man International | B23 Sicilian, Closed |
| 12. I Marks vs M Ferguson |
| 0-1 | 37 |
2007 |
Isle of Man International | C97 Ruy Lopez, Closed, Chigorin |
| 13. K Smokina vs I Marks |
| 1-0 | 45 |
2007 |
Isle of Man International | A46 Queen's Pawn Game |
| 14. J Van den Bersselaar vs I Marks |
| 0-1 | 89 |
2007 |
Isle of Man International | E40 Nimzo-Indian, 4.e3 |
| 15. I Marks vs M Weeks |
| ½-½ | 21 |
2007 |
Isle of Man International | C81 Ruy Lopez, Open, Howell Attack |
| 16. O Jackson vs I Marks |
| 1-0 | 52 |
2007 |
Isle of Man International | B23 Sicilian, Closed |
| 17. P Hughes vs I Marks |
| ½-½ | 36 |
2008 |
Gibraltar | E11 Bogo-Indian Defense |
| 18. I Marks vs M Goodger |
 | 0-1 | 39 |
2008 |
Gibraltar | A90 Dutch |
| 19. I Marks vs P Svendsen |
 | 0-1 | 20 |
2008 |
Gibraltar | B09 Pirc, Austrian Attack |
| 20. I Marks vs F Garcia Lechugo |
| 1-0 | 54 |
2008 |
Gibraltar | B06 Robatsch |
| 21. I Marks vs H Mortensen |
| 0-1 | 22 |
2008 |
Gibraltar | B33 Sicilian |
| 22. T Vasvari vs I Marks |
| 1-0 | 25 |
2008 |
Gibraltar | B96 Sicilian, Najdorf |
| 23. G Matto vs I Marks |
| 0-1 | 27 |
2008 |
Gibraltar | B50 Sicilian |
| 24. J Ocana Roca vs I Marks |
| 1-0 | 26 |
2008 |
Gibraltar | B90 Sicilian, Najdorf |
| 25. M Lode vs I Marks |
| 0-1 | 20 |
2008 |
Gibraltar | B96 Sicilian, Najdorf |