| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 26. L Rellstab vs B Koch |
| ½-½ | 40 | 1929 | Berlin ch | D48 Queen's Gambit Declined Semi-Slav, Meran |
| 27. B Koch vs I Engert |
| 1-0 | 33 | 1929 | Berlin ch | B40 Sicilian |
| 28. B Koch vs A Babel |
| 1-0 | 37 | 1929 | Berlin ch | D05 Queen's Pawn Game |
| 29. C Ahues vs B Koch |
| ½-½ | 41 | 1929 | Berlin ch | D30 Queen's Gambit Declined |
| 30. G Katz vs B Koch |
| 0-1 | 31 | 1930 | Wilmersdorf CC Jubilee | B17 Caro-Kann, Steinitz Variation |
| 31. K Richter vs B Koch |
| 1-0 | 35 | 1930 | Berlin Championship | D01 Richter-Veresov Attack |
| 32. Saemisch vs B Koch |
| 1-0 | 32 | 1930 | Swinemuende | D52 Queen's Gambit Declined |
| 33. B Koch vs L Rellstab |
| 0-1 | 26 | 1930 | Swinemuende | E10 Queen's Pawn Game |
| 34. Stahlberg vs B Koch |
 | 0-1 | 36 | 1930 | Swinemuende | D36 Queen's Gambit Declined, Exchange, Positional line, 6.Qc2 |
| 35. E Andersen vs B Koch |
| 1-0 | 55 | 1930 | Swinemuende | D48 Queen's Gambit Declined Semi-Slav, Meran |
| 36. B Koch vs K Pahl |
| ½-½ | 33 | 1930 | Swinemuende | D02 Queen's Pawn Game |
| 37. H Wagner vs B Koch |
| ½-½ | 21 | 1930 | Swinemuende | A82 Dutch, Staunton Gambit |
| 38. B Koch vs Flohr |
| 0-1 | 51 | 1930 | Swinemuende | A43 Old Benoni |
| 39. K Richter vs B Koch |
| 1-0 | 37 | 1930 | Swinemuende | D04 Queen's Pawn Game |
| 40. B Koch vs G Stoltz |
 | 0-1 | 37 | 1930 | Swinemuende | A46 Queen's Pawn Game |
| 41. B Koch vs S Fuchs |
| 1-0 | 31 | 1930 | Zoppot | D12 Queen's Gambit Declined Slav |
| 42. L Rellstab vs B Koch |
| ½-½ | 37 | 1930 | Sopot | B13 Caro-Kann, Exchange |
| 43. B Koch vs P Frydman |
| ½-½ | 45 | 1930 | Zoppot | D05 Queen's Pawn Game |
| 44. B Koch vs I Appel |
| ½-½ | 32 | 1930 | Zoppot | A46 Queen's Pawn Game |
| 45. S Kohn vs B Koch |
| ½-½ | 56 | 1930 | Zoppot | D30 Queen's Gambit Declined |
| 46. B Koch vs P Leonhardt |
| 1-0 | 39 | 1930 | Zoppot | D05 Queen's Pawn Game |
| 47. G Stoltz vs B Koch |
| 0-1 | 44 | 1930 | Zoppot | B16 Caro-Kann, Bronstein-Larsen Variation |
| 48. L Roedl vs B Koch |
| 0-1 | 41 | 1931 | 27th German Chess Federation Congress | B58 Sicilian |
| 49. Saemisch vs B Koch |
| 1-0 | 36 | 1931 | 27th German Chess Federation Congress | D51 Queen's Gambit Declined |
| 50. B Koch vs Bogoljubov |
| 0-1 | 48 | 1931 | 27th German Chess Federation Congress | D95 Grunfeld |
Kibitzing
