| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 26. K Rozic vs I Koenig |
| 0-1 | 35 | 1929 | Rogaska Slatina | A83 Dutch, Staunton Gambit |
| 27. S Boros vs I Koenig |
| 0-1 | 24 | 1931 | Trebitsch Memorial 14th | D31 Queen's Gambit Declined |
| 28. I Koenig vs F Kunert |
| 1-0 | 29 | 1931 | Trebitsch Memorial 14th | B58 Sicilian |
| 29. I Koenig vs L Metanomski |
| 1-0 | 35 | 1931 | Trebitsch Memorial 14th | D55 Queen's Gambit Declined |
| 30. I Koenig vs Duchamp |
| 1-0 | 31 | 1931 | Prague Olympiad | E12 Queen's Indian |
| 31. I Koenig vs E Lundin |
 | 1-0 | 38 | 1931 | Prague Olympiad | D66 Queen's Gambit Declined, Orthodox Defense, Bd3 line |
| 32. M Luckis vs I Koenig |
| 0-1 | 29 | 1931 | Prague Olympiad | C45 Scotch Game |
| 33. E Hellmann vs I Koenig |
| 0-1 | 42 | 1931 | Prague Olympiad | A02 Bird's Opening |
| 34. I Koenig vs W Michel |
| ½-½ | 40 | 1931 | Prague Olympiad | C97 Ruy Lopez, Closed, Chigorin |
| 35. J Sanz vs I Koenig |
| 0-1 | 45 | 1931 | Prague Olympiad | C84 Ruy Lopez, Closed |
| 36. I Koenig vs V Tomovic |
| 0-1 | 30 | 1935 | YUG-ch | E41 Nimzo-Indian |
| 37. I Koenig vs E Sorensen |
| 1-0 | 23 | 1935 | Warsaw Olympiad | C86 Ruy Lopez, Worrall Attack |
| 38. I Koenig vs T Salo |
| 1-0 | 36 | 1935 | Warsaw Olympiad | B58 Sicilian |
| 39. I Koenig vs I Raud |
| 1-0 | 49 | 1935 | Warsaw Olympiad | C74 Ruy Lopez, Modern Steinitz Defense |
| 40. Golombek vs I Koenig |
| ½-½ | 30 | 1935 | Warsaw Olympiad | A18 English, Mikenas-Carls |
| 41. I Koenig vs Pelikan |
| ½-½ | 30 | 1935 | Warsaw Olympiad | D67 Queen's Gambit Declined, Orthodox Defense, Bd3 line |
| 42. I Koenig vs P Rethy |
| 0-1 | 75 | 1935 | Warsaw Olympiad | A04 Reti Opening |
| 43. G Danielsson vs I Koenig |
| ½-½ | 62 | 1935 | Warsaw Olympiad | E24 Nimzo-Indian, Samisch |
| 44. I Koenig vs M Napolitano |
| ½-½ | 59 | 1935 | Warsaw Olympiad | B10 Caro-Kann |
| 45. Edgars Krumins vs I Koenig |
| 1-0 | 46 | 1935 | Warsaw Olympiad | A47 Queen's Indian |
| 46. I Koenig vs W Hasenfuss |
| 1-0 | 24 | 1936 | non-FIDE Munich Olympiad | C40 King's Knight Opening |
| 47. T D van Scheltinga vs I Koenig |
| 0-1 | 29 | 1936 | non-FIDE Munich Olympiad | E32 Nimzo-Indian, Classical |
| 48. I Koenig vs B N Rometti |
| 1-0 | 30 | 1936 | non-FIDE Munich Olympiad | B10 Caro-Kann |
| 49. I Koenig vs Olof Kinnmark |
| 1-0 | 36 | 1936 | non-FIDE Munich Olympiad | C14 French, Classical |
| 50. I Koenig vs A Kiprov |
| 1-0 | 41 | 1936 | non-FIDE Munich Olympiad | B10 Caro-Kann |
Kibitzing
