| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 26. L Genova vs M Mostertman |
| 1-0 | 50 | 2009 | 13th Unive Tournament (Open) | B01 Scandinavian |
| 27. M Mostertman vs M Admiraal |
| ½-½ | 19 | 2009 | 13th Unive Tournament (Open) | B83 Sicilian |
| 28. A Pijpers vs M Mostertman |
| ½-½ | 18 | 2009 | 13th Unive Tournament (Open) | B77 Sicilian, Dragon, Yugoslav Attack |
| 29. M Mostertman vs P Genov |
 | 0-1 | 23 | 2009 | Groningen Chess Festival | B84 Sicilian, Scheveningen |
| 30. M Berkovich vs M Mostertman |
| 1-0 | 28 | 2009 | Groningen Chess Festival | A46 Queen's Pawn Game |
| 31. M Mostertman vs U Hirth |
| 1-0 | 48 | 2009 | Groningen Chess Festival | B06 Robatsch |
| 32. D Klein vs M Mostertman |
| ½-½ | 24 | 2009 | Groningen Chess Festival | B76 Sicilian, Dragon, Yugoslav Attack |
| 33. M Mostertman vs I Werle |
| 1-0 | 35 | 2009 | Groningen Chess Festival | B87 Sicilian, Fischer-Sozin with ...a6 and ...b5 |
| 34. M Hoffmann vs M Mostertman |
| 1-0 | 21 | 2009 | Groningen Chess Festival | A15 English |
| 35. L Genova vs M Mostertman |
| 1-0 | 21 | 2009 | Groningen Chess Festival | B01 Scandinavian |
| 36. M Mostertman vs M Lyell |
| 1-0 | 36 | 2009 | Groningen Chess Festival | C58 Two Knights |
| 37. E Hoeksema vs M Mostertman |
| 1-0 | 63 | 2009 | Groningen Chess Festival | A15 English |
| 38. V Neverov vs M Mostertman |
| 1-0 | 24 | 2010 | Dutch Open | E28 Nimzo-Indian, Samisch Variation |
| 39. C Kleijn vs M Mostertman |
| 1-0 | 44 | 2010 | NED-chT | B50 Sicilian |
| 40. M Martens vs M Mostertman |
| 1-0 | 52 | 2010 | NED-chT | B30 Sicilian |
| 41. M Mostertman vs Turov |
| 0-1 | 32 | 2011 | Dutch Open | C53 Giuoco Piano |
| 42. M Viergever vs M Mostertman |
| 0-1 | 39 | 2011 | Dutch Open | B22 Sicilian, Alapin |
| 43. M Mostertman vs J van Foreest |
| 1-0 | 52 | 2011 | Dutch Open | B92 Sicilian, Najdorf, Opocensky Variation |
| 44. I Turova vs M Mostertman |
| 1-0 | 32 | 2011 | Dutch Open | A52 Budapest Gambit |
| 45. M Mostertman vs M Timmermans |
| ½-½ | 15 | 2011 | Dutch Open | C58 Two Knights |
| 46. F Lommers vs M Mostertman |
| 1-0 | 36 | 2011 | Dutch Open | A14 English |
| 47. M Mostertman vs T Koffeman |
| 1-0 | 20 | 2011 | Dutch Open | B46 Sicilian, Taimanov Variation |
| 48. L van der Linden vs M Mostertman |
| ½-½ | 42 | 2011 | Dutch Open | E47 Nimzo-Indian, 4.e3 O-O 5.Bd3 |
| 49. M Mostertman vs Deepan Chakkravarthy J |
| 0-1 | 58 | 2011 | Dutch Open | B84 Sicilian, Scheveningen |
| 50. M Mostertman vs V David |
| 0-1 | 23 | 2012 | 27th Avoine Open | C10 French |
Kibitzing
