| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 26. P de Rooi vs B Sandor |
| 1-0 | 73 | 1963 | Hoogovens-B1 | B07 Pirc |
| 27. A Dunkelblum vs P de Rooi |
| ½-½ | 18 | 1963 | Hoogovens-B1 | A15 English |
| 28. P de Rooi vs L Rellstab |
| ½-½ | 55 | 1963 | Hoogovens-B1 | C68 Ruy Lopez, Exchange |
| 29. C Zuidema vs P de Rooi |
| 1-0 | 41 | 1963 | Hoogovens-B1 | B32 Sicilian |
| 30. P de Rooi vs E Ditt |
| 1-0 | 58 | 1963 | Hoogovens-B1 | C61 Ruy Lopez, Bird's Defense |
| 31. R G Wade vs P de Rooi |
| 0-1 | 26 | 1963 | Hoogovens-B1 | C11 French |
| 32. P de Rooi vs Portisch |
 | 0-1 | 33 | 1963 | Amsterdam IBM | C68 Ruy Lopez, Exchange |
| 33. M Udovcic vs P de Rooi |
| 1-0 | 26 | 1963 | Amsterdam IBM | E62 King's Indian, Fianchetto |
| 34. P de Rooi vs J Barendregt |
| 0-1 | 36 | 1963 | Amsterdam IBM | B07 Pirc |
| 35. B Milic vs P de Rooi |
| 1-0 | 42 | 1963 | Amsterdam IBM | B32 Sicilian |
| 36. P de Rooi vs K Langeweg |
| 0-1 | 44 | 1963 | Amsterdam IBM | A07 King's Indian Attack |
| 37. J H Donner vs P de Rooi |
| 1-0 | 29 | 1963 | Amsterdam IBM | E62 King's Indian, Fianchetto |
| 38. P de Rooi vs M Czerniak |
| 1-0 | 44 | 1963 | Amsterdam IBM | A16 English |
| 39. P de Rooi vs Parma |
| ½-½ | 28 | 1963 | Amsterdam IBM | A16 English |
| 40. F Kuijpers vs P de Rooi |
| 1-0 | 36 | 1963 | Amsterdam IBM | A07 King's Indian Attack |
| 41. T Krabbe vs P de Rooi |
| 1-0 | 22 | 1964 | NED-ch prelim | B17 Caro-Kann, Steinitz Variation |
| 42. P de Rooi vs Filip |
| 0-1 | 39 | 1964 | Hoogovens | B42 Sicilian, Kan |
| 43. J H Donner vs P de Rooi |
| ½-½ | 53 | 1964 | Hoogovens | A40 Queen's Pawn Game |
| 44. P de Rooi vs A Dunkelblum |
| ½-½ | 23 | 1964 | Hoogovens | C15 French, Winawer |
| 45. Ivkov vs P de Rooi |
| 1-0 | 46 | 1964 | Hoogovens | D37 Queen's Gambit Declined |
| 46. Portisch vs P de Rooi |
| 1-0 | 36 | 1964 | Hoogovens | E71 King's Indian, Makagonov System (5.h3) |
| 47. Larsen vs P de Rooi |
| 1-0 | 43 | 1964 | Hoogovens | E71 King's Indian, Makagonov System (5.h3) |
| 48. P de Rooi vs T van Scheltinga |
| 0-1 | 34 | 1964 | Hoogovens | A17 English |
| 49. C Zuidema vs P de Rooi |
| 1-0 | 42 | 1964 | Hoogovens | B32 Sicilian |
| 50. P de Rooi vs Bobotsov |
| 0-1 | 27 | 1964 | Hoogovens | A16 English |
Kibitzing
