| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 51. H Rossetto vs H Seidman |
 | 1-0 | 38 | 1945 | 1st Pan-American Championship | D78 Neo-Grunfeld, 6.O-O c6 |
| 52. H Seidman vs I A Horowitz |
| 0-1 | 43 | 1945 | 1st Pan-American Championship | C59 Two Knights |
| 53. J Broderman vs H Seidman |
 | 0-1 | 47 | 1945 | 1st Pan-American Championship | B73 Sicilian, Dragon, Classical |
| 54. H Seidman vs Pilnik |
| 0-1 | 36 | 1945 | 1st Pan-American Championship | B45 Sicilian, Taimanov |
| 55. J Camarena vs H Seidman |
| 0-1 | 29 | 1945 | 1st Pan-American Championship | A48 King's Indian |
| 56. H Seidman vs W O Cruz |
| ½-½ | 41 | 1945 | 1st Pan-American Championship | C52 Evans Gambit |
| 57. W Adams vs H Seidman |
| 1-0 | 38 | 1945 | 1st Pan-American Championship | B45 Sicilian, Taimanov |
| 58. Ragozin vs H Seidman |
| 1-0 | 49 | 1945 | USSR - USA Radio Match | E44 Nimzo-Indian, Fischer Variation, 5.Ne2 |
| 59. H Seidman vs Ragozin |
| 0-1 | 68 | 1945 | USSR - USA Radio Match | C59 Two Knights |
| 60. Santasiere vs H Seidman |
| 1-0 | 27 | 1946 | Marshall CC-ch (1945/46) Play-off | B02 Alekhine's Defense |
| 61. Santasiere vs H Seidman |
| 1-0 | 45 | 1946 | Marshall CC-ch (1945/46) Play-off | A22 English |
| 62. H Seidman vs Santasiere |
| 1-0 | 74 | 1946 | Marshall CC-ch (1945/46) Play-off | E33 Nimzo-Indian, Classical |
| 63. H Seidman vs Santasiere |
| 1-0 | 45 | 1946 | Marshall CC-ch (1945/46) Play-off | E46 Nimzo-Indian |
| 64. H Gordon vs H Seidman |
| 0-1 | 48 | 1946 | 47th US Open | D80 Grunfeld |
| 65. H Seidman vs E Strang |
| 1-0 | 56 | 1946 | 47th US Open | E40 Nimzo-Indian, 4.e3 |
| 66. H Seidman vs W Adams |
| 1-0 | 40 | 1946 | 47th US Open | C52 Evans Gambit |
| 67. D Byrne vs H Seidman |
| 1-0 | 47 | 1946 | 47th US Open | E14 Queen's Indian |
| 68. H Seidman vs G Kramer |
| 1-0 | 27 | 1946 | 47th US Open | C80 Ruy Lopez, Open |
| 69. M Aleman Dovo vs H Seidman |
| ½-½ | 31 | 1946 | 47th US Open | A07 King's Indian Attack |
| 70. H Seidman vs O Ulvestad |
| 0-1 | 53 | 1946 | 47th US Open | B00 Uncommon King's Pawn Opening |
| 71. O Shapiro vs H Seidman |
| 0-1 | 35 | 1946 | 47th US Open | D93 Grunfeld, with Bf4 & e3 |
| 72. H Steiner vs H Seidman |
| ½-½ | 117 | 1946 | 47th US Open | B45 Sicilian, Taimanov |
| 73. H Seidman vs G Katz |
| 1-0 | 49 | 1946 | 47th US Open | C86 Ruy Lopez, Worrall Attack |
| 74. A Bisguier vs H Seidman |
| 0-1 | 47 | 1946 | 47th US Open | A28 English |
| 75. H Seidman vs H Fajans |
| ½-½ | 66 | 1946 | 47th US Open | C45 Scotch Game |
Kibitzing
