| Game |
| Result | Moves |
Year |
Event/Locale | Opening |
| 26. K Langeweg vs Parma |
| ½-½ | 20 |
1962 |
Olympiad | E11 Bogo-Indian Defense |
| 27. F Kuijpers vs K Langeweg |
| 1-0 | 39 |
1963 |
NED-ch21 | B43 Sicilian, Kan, 5.Nc3 |
| 28. Averbakh vs K Langeweg |
| 1-0 | 36 |
1963 |
Hoogovens | A53 Old Indian |
| 29. T Van Scheltinga vs K Langeweg |
| 0-1 | 34 |
1963 |
Hoogovens | A62 Benoni, Fianchetto Variation |
| 30. K Langeweg vs Portisch |
| 0-1 | 23 |
1963 |
Amsterdam | E12 Queen's Indian |
| 31. K Langeweg vs O'Kelly |
| 1-0 | 47 |
1963 |
Hoogovens | A39 English, Symmetrical, Main line with d4 |
| 32. F Kuijpers vs K Langeweg |
| 1-0 | 57 |
1963 |
IBM | B48 Sicilian, Taimanov Variation |
| 33. Pilnik vs K Langeweg |
| 1-0 | 25 |
1963 |
Hoogovens | B47 Sicilian, Taimanov (Bastrikov) Variation |
| 34. K Langeweg vs Bronstein |
 | 0-1 | 30 |
1963 |
Beverwijk | A13 English |
| 35. K Langeweg vs Ivkov |
| ½-½ | 12 |
1963 |
Beverwijk | A10 English |
| 36. E Gereben vs K Langeweg |
| 0-1 | 54 |
1963 |
Hoogovens | A43 Old Benoni |
| 37. K Langeweg vs M Czerniak |
| 0-1 | 27 |
1963 |
IBM | E92 King's Indian |
| 38. K Langeweg vs B Milic |
| 0-1 | 34 |
1963 |
Hoogovens | A10 English |
| 39. K Langeweg vs Robatsch |
| ½-½ | 35 |
1963 |
Beverwijk | A08 King's Indian Attack |
| 40. J H Donner vs K Langeweg |
| 1-0 | 42 |
1963 |
Hoogovens | A61 Benoni |
| 41. Pirc vs K Langeweg |
| 0-1 | 25 |
1963 |
Hoogovens | A04 Reti Opening |
| 42. K Langeweg vs Stahlberg |
| 0-1 | 17 |
1963 |
Hoogovens | A10 English |
| 43. C B Van den Berg vs K Langeweg |
| 1-0 | 23 |
1963 |
Hoogovens | B46 Sicilian, Taimanov Variation |
| 44. Parma vs K Langeweg |
| 1-0 | 41 |
1963 |
Beverwijk | B46 Sicilian, Taimanov Variation |
| 45. K Langeweg vs P Trifunovic |
| ½-½ | 14 |
1963 |
Hoogovens | E10 Queen's Pawn Game |
| 46. Tan Hiong Liong vs K Langeweg |
| ½-½ | 27 |
1963 |
Hoogovens | A46 Queen's Pawn Game |
| 47. K Langeweg vs A Matanovic |
| ½-½ | 41 |
1963 |
Hoogovens | A17 English |
| 48. K Langeweg vs Z Vranesic |
| 1-0 | 22 |
1964 |
Tel Aviv ol (Men) fin-A | B43 Sicilian, Kan, 5.Nc3 |
| 49. K Langeweg vs A Prameshuber |
| ½-½ | 43 |
1964 |
Kecskemet zt | A42 Modern Defense, Averbakh System |
| 50. Bagirov vs K Langeweg |
| 1-0 | 41 |
1964 |
Beverwijk | B44 Sicilian |