| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 1. C B Van den Berg vs K Langeweg |
| ½-½ | 27 |
1959 |
Hoogovens | B90 Sicilian, Najdorf |
| 2. C B Van den Berg vs K Langeweg |
| 0-1 | 35 |
1961 |
IBM | B96 Sicilian, Najdorf |
| 3. Minev vs K Langeweg |
| ½-½ | 30 |
1962 |
Varna ol (Men) fin-A | B25 Sicilian, Closed |
| 4. E Paoli vs K Langeweg |
| 0-1 | 47 |
1962 |
Reggio Emilia 6263 | B48 Sicilian, Taimanov Variation |
| 5. L Zinn vs K Langeweg |
 | 0-1 | 40 |
1962 |
Varna ol (Men) fin-A | B43 Sicilian, Kan, 5.Nc3 |
| 6. A Matanovic vs K Langeweg |
| ½-½ | 31 |
1962 |
Varna ol (Men) fin-A | B42 Sicilian, Kan |
| 7. Schmid vs K Langeweg |
| 1-0 | 31 |
1962 |
Clare Benedict Cup 09th | B43 Sicilian, Kan, 5.Nc3 |
| 8. F Kuijpers vs K Langeweg |
| 1-0 | 39 |
1963 |
NED-ch21 | B43 Sicilian, Kan, 5.Nc3 |
| 9. Pilnik vs K Langeweg |
| 1-0 | 25 |
1963 |
Hoogovens | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 10. F Kuijpers vs K Langeweg |
| 1-0 | 57 |
1963 |
IBM | B48 Sicilian, Taimanov Variation |
| 11. C B Van den Berg vs K Langeweg |
| 1-0 | 23 |
1963 |
Hoogovens | B46 Sicilian, Taimanov Variation |
| 12. Parma vs K Langeweg |
| 1-0 | 41 |
1963 |
Beverwijk | B46 Sicilian, Taimanov Variation |
| 13. Szabo vs K Langeweg |
 | 1-0 | 27 |
1964 |
Kecskemet | B43 Sicilian, Kan, 5.Nc3 |
| 14. Tringov vs K Langeweg |
| ½-½ | 41 |
1964 |
Tel Aviv ol (Men) fin-A | B48 Sicilian, Taimanov Variation |
| 15. Bagirov vs K Langeweg |
| 1-0 | 41 |
1964 |
Beverwijk | B44 Sicilian |
| 16. Schmid vs K Langeweg |
| ½-½ | 41 |
1964 |
Tel Aviv ol (Men) fin-A | B83 Sicilian |
| 17. I Nei vs K Langeweg |
| 1-0 | 32 |
1966 |
Hoogovens 28th | B44 Sicilian |
| 18. Robatsch vs K Langeweg |
| ½-½ | 18 |
1967 |
NED | B82 Sicilian, Scheveningen |
| 19. F Kuijpers vs K Langeweg |
| 1-0 | 26 |
1967 |
Hoogovens | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 20. Karaklajic vs K Langeweg |
| ½-½ | 41 |
1968 |
Wijk aan Zee I | B44 Sicilian |
| 21. Keres vs K Langeweg |
| 1-0 | 52 |
1969 |
Wijk aan Zee (21.01.69) | B27 Sicilian |
| 22. Kavalek vs K Langeweg |
| 1-0 | 40 |
1969 |
Wijk aan Zee I | B32 Sicilian |
| 23. Vasiukov vs K Langeweg |
| 1-0 | 38 |
1969 |
IBM | B54 Sicilian |
| 24. F Kuijpers vs K Langeweg |
| 0-1 | 67 |
1969 |
NED-ch | B64 Sicilian, Richter-Rauzer Attack |
| 25. Tringov vs K Langeweg |
| ½-½ | 47 |
1970 |
IBM | B43 Sicilian, Kan, 5.Nc3 |