| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. J H Donner vs J Kupper |
| 1-0 | 35 |
1953 |
Opatija | E59 Nimzo-Indian, 4.e3, Main line |
| 2. J Kupper vs B Rabar |
| ½-½ | 40 |
1953 |
Opatija | B93 Sicilian, Najdorf, 6.f4 |
| 3. J Kupper vs M Bertok |
| ½-½ | 36 |
1953 |
Opatija | B93 Sicilian, Najdorf, 6.f4 |
| 4. Szabo vs J Kupper |
| ½-½ | 48 |
1954 |
Amsterdam olm prel | E29 Nimzo-Indian, Samisch |
| 5. J Kupper vs Schmid |
| 0-1 | 40 |
1954 |
Zuerich | C18 French, Winawer |
| 6. J Kupper vs M Cuellar Gacharna |
| 1-0 | 41 |
1954 |
Amsterdam ol (Men) | B71 Sicilian, Dragon, Levenfish Variation |
| 7. Yanofsky vs J Kupper |
| 0-1 | 62 |
1954 |
Amsterdam | B93 Sicilian, Najdorf, 6.f4 |
| 8. J Kupper vs T Kelly |
| ½-½ | 36 |
1954 |
Amsterdam ol (Men) | B64 Sicilian, Richter-Rauzer Attack |
| 9. J Kupper vs C H Alexander |
| 0-1 | 40 |
1954 |
Amsterdam ol (Men) | B07 Pirc |
| 10. J Kupper vs C Doerner |
| 1-0 | 53 |
1954 |
Amsterdam ol (Men) | C85 Ruy Lopez, Exchange Variation Doubly Deferred (DERLD) |
| 11. J Kupper vs A Vestol |
| 1-0 | 35 |
1954 |
Amsterdam | B93 Sicilian, Najdorf, 6.f4 |
| 12. A Dunkelblum vs J Kupper |
| ½-½ | 34 |
1954 |
Amsterdam ol (Men) | E17 Queen's Indian |
| 13. Robatsch vs J Kupper |
| 0-1 | 53 |
1954 |
Amsterdam ol (Men) | A04 Reti Opening |
| 14. J Kupper vs E Bhend |
| ½-½ | 29 |
1954 |
Zuerich | B93 Sicilian, Najdorf, 6.f4 |
| 15. O Benkner vs J Kupper |
| 1-0 | 46 |
1954 |
Amsterdam ol (Men) | A35 English, Symmetrical |
| 16. J Kupper vs T Salo |
| 1-0 | 80 |
1954 |
Amsterdam ol (Men) | B93 Sicilian, Najdorf, 6.f4 |
| 17. J Kupper vs O Bernstein |
| 1-0 | 33 |
1954 |
Amsterdam ol (Men) | C62 Ruy Lopez, Old Steinitz Defense |
| 18. J Kupper vs E Paoli |
| 1-0 | 60 |
1954 |
Amsterdam ol (Men) fin-B | C64 Ruy Lopez, Classical |
| 19. O'Kelly vs J Kupper |
| ½-½ | 15 |
1954 |
Amsterdam ol (Men) | A34 English, Symmetrical |
| 20. J Kupper vs Stahlberg |
| ½-½ | 23 |
1958 |
13th olm qual. group 4 | C14 French, Classical |
| 21. J Kupper vs Uhlmann |
| ½-½ | 42 |
1958 |
13th olm final A | C05 French, Tarrasch |
| 22. K Lagha vs J Kupper |
| 0-1 | 46 |
1958 |
13th olm qual. group 4 | E12 Queen's Indian |
| 23. J Kupper vs E Paoli |
| 1-0 | 41 |
1958 |
Clare Benedict Cup 05th | B64 Sicilian, Richter-Rauzer Attack |
| 24. J Kupper vs Panno |
| 0-1 | 78 |
1958 |
13th olm final A | B69 Sicilian, Richter-Rauzer Attack, 7...a6 Defense, 11.Bxf6 |
| 25. J Kupper vs P Vaitonis |
| ½-½ | 26 |
1958 |
13th olm qual. group 4 | B93 Sicilian, Najdorf, 6.f4 |