| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 51. R Hartoch vs A Dueckstein |
| 0-1 | 41 | 1966 | Amsterdam IBM-B | C17 French, Winawer, Advance |
| 52. A Konstantinopolsky vs R Hartoch |
| ½-½ | 28 | 1966 | Amsterdam IBM-B | A05 Reti Opening |
| 53. R Hartoch vs T Ghitescu |
| 0-1 | 30 | 1966 | Amsterdam IBM-B | A25 English |
| 54. R Hartoch vs E Scholl |
| 0-1 | 43 | 1966 | Amsterdam IBM-B | C91 Ruy Lopez, Closed |
| 55. J Enevoldsen vs R Hartoch |
| 1-0 | 59 | 1966 | Amsterdam IBM-B | C26 Vienna |
| 56. R Hartoch vs P Bakker |
| ½-½ | 21 | 1966 | Amsterdam IBM-B | A97 Dutch, Ilyin-Genevsky |
| 57. L Kerkhoff vs R Hartoch |
| 0-1 | 49 | 1966 | Amsterdam IBM-B | C84 Ruy Lopez, Closed |
| 58. Timman vs R Hartoch |
 | 0-1 | 37 | 1967 | Amsterdam IBM III | E87 King's Indian, Samisch, Orthodox |
| 59. R Hartoch vs S Tatai |
| 0-1 | 40 | 1968 | Hoogovens-B | B87 Sicilian, Fischer-Sozin with ...a6 and ...b5 |
| 60. P Ostojic vs R Hartoch |
| 1-0 | 53 | 1968 | Hoogovens-B | C75 Ruy Lopez, Modern Steinitz Defense |
| 61. R Hartoch vs A Vyslouzil |
| 1-0 | 40 | 1968 | Hoogovens-B | B45 Sicilian, Taimanov |
| 62. T van Scheltinga vs R Hartoch |
| 1-0 | 40 | 1968 | Hoogovens-B | E69 King's Indian, Fianchetto, Classical Main line |
| 63. R Hartoch vs D Marovic |
| ½-½ | 41 | 1968 | Hoogovens-B | A00 Uncommon Opening |
| 64. B Zuckerman vs R Hartoch |
 | 1-0 | 19 | 1968 | Hoogovens-B | C72 Ruy Lopez, Modern Steinitz Defense, 5.O-O |
| 65. R Hartoch vs H Crabbendam |
| 1-0 | 39 | 1968 | Hoogovens-B | B96 Sicilian, Najdorf |
| 66. V Ciocaltea vs R Hartoch |
| 1-0 | 57 | 1968 | Hoogovens-B | C94 Ruy Lopez, Closed, Breyer Defense |
| 67. R Hartoch vs S Nikolic |
| 0-1 | 51 | 1968 | Hoogovens-B | B98 Sicilian, Najdorf |
| 68. R Hartoch vs A Jongsma |
| 1-0 | 51 | 1968 | Hoogovens-B | B35 Sicilian, Accelerated Fianchetto, Modern Variation with Bc4 |
| 69. Z Doda vs R Hartoch |
| 1-0 | 37 | 1968 | Hoogovens-B | A04 Reti Opening |
| 70. R Hartoch vs A Medina Garcia |
| ½-½ | 46 | 1968 | Hoogovens-B | B44 Sicilian |
| 71. J Flesch vs R Hartoch |
| ½-½ | 49 | 1968 | Hoogovens-B | A07 King's Indian Attack |
| 72. R Hartoch vs M Ujtelky |
| ½-½ | 72 | 1968 | Hoogovens-B | B06 Robatsch |
| 73. A Dunkelblum vs R Hartoch |
| ½-½ | 23 | 1968 | Hoogovens-B | A10 English |
| 74. R Hartoch vs E Gereben |
| 1-0 | 40 | 1968 | Amsterdam IBM-B | C72 Ruy Lopez, Modern Steinitz Defense, 5.O-O |
| 75. D van Geet vs R Hartoch |
| 0-1 | 50 | 1968 | Amsterdam IBM-B | C47 Four Knights |
Kibitzing
