| Game |
| Result | Moves |
Year | Event/Locale | Opening |
| 26. R F McGregor vs S Popel |
| 0-1 | 28 | 1956 | 57th US Open | A27 English, Three Knights System |
| 27. J F Shaw vs S Popel |
| 1-0 | 23 | 1956 | 57th US Open | A52 Budapest Gambit |
| 28. S Popel vs Kamalakar Raut |
| 1-0 | 34 | 1956 | 57th US Open | E69 King's Indian, Fianchetto, Classical Main line |
| 29. E Mednis vs S Popel |
| ½-½ | 40 | 1956 | 57th US Open | B01 Scandinavian |
| 30. S Popel vs O Popovych |
 | 0-1 | 42 | 1956 | 57th US Open | A49 King's Indian, Fianchetto without c4 |
| 31. B Garfinkel vs S Popel |
 | 0-1 | 30 | 1956 | 57th US Open | E80 King's Indian, Samisch Variation |
| 32. S Popel vs C R Freeman |
| 1-0 | 36 | 1956 | 57th US Open | D78 Neo-Grunfeld, 6.O-O c6 |
| 33. S Popel vs D Fischheimer |
| 1-0 | 53 | 1956 | 57th US Open | A04 Reti Opening |
| 34. S Popel vs A Saidy |
| ½-½ | 60 | 1956 | 57th US Open | A04 Reti Opening |
| 35. Fischer vs S Popel |
| ½-½ | 38 | 1956 | 57th US Open | A07 King's Indian Attack |
| 36. S Popel vs B E Owens |
| 1-0 | 44 | 1956 | 57th US Open | A04 Reti Opening |
| 37. S Popel vs G Mauer |
| 1-0 | 31 | 1958 | 59th US Open | A04 Reti Opening |
| 38. S Popel vs H Gross |
| 1-0 | 48 | 1958 | 59th US Open | A06 Reti Opening |
| 39. A Bisguier vs S Popel |
| 1-0 | 44 | 1958 | 59th US Open | E11 Bogo-Indian Defense |
| 40. S Popel vs J Hudson |
| 1-0 | 47 | 1958 | 59th US Open | A04 Reti Opening |
| 41. S Popel vs A Kaufman |
| 1-0 | 35 | 1958 | 59th US Open | A04 Reti Opening |
| 42. F Ballbe Anglada vs S Popel |
| 0-1 | 46 | 1958 | 59th US Open | B01 Scandinavian |
| 43. R Byrne vs S Popel |
| 1-0 | 99 | 1958 | 59th US Open | E50 Nimzo-Indian, 4.e3 O-O 5.Nf3, without ...d5 |
| 44. S Popel vs E Marchand |
| 1-0 | 35 | 1958 | 59th US Open | A06 Reti Opening |
| 45. R H Steinmeyer vs S Popel |
| 1-0 | 45 | 1960 | corr | B01 Scandinavian |
| 46. S Popel vs R Chalker |
| 0-1 | 14 | 1969 | 70th US Open | A35 English, Symmetrical |
| 47. J L Watson vs S Popel |
| 0-1 | 42 | 1969 | 70th US Open | C02 French, Advance |
| 48. Benko vs S Popel |
| 1-0 | 27 | 1969 | 70th US Open | A21 English |
| 49. S Popel vs J Horton |
| 0-1 | 50 | 1969 | 70th US Open | A31 English, Symmetrical, Benoni Formation |
| 50. J Westbrock vs S Popel |
| 0-1 | 46 | 1969 | 70th US Open | E00 Queen's Pawn Game |
Kibitzing
