Pawn and Two: Because of the result of a game, mistakes of the winner and possibilities for the loser are often overlooked.In this game, Halprin had a strong advantage after the opening 11 moves.
Fritz 9 evaluates the positon after move 11 as favoring White (1.25) (16 ply). Fritz then recommends 12. Qd1-f3 c6-c5 13. Ne5xd7 Nf6xd7 14. Ra1-d1 c5xd4.
Instead, Halprin played 12. f4-f5??. Fritz evaluates this position as slightly unfavorable for White (-.06) (16 ply) and gives the following line: 12. f4-f5 exf5 13. exf5 Rf8-e8 14. Rf1-e1 Qd8-c7.
At move 19, Maroczy made a gross blunder. The tournament book states that Maroczy only took into account the reply 20. Be3-f2, when he could have answered with 20. Bc8xf5.
The tournament book stated that the position could still be held if Black had played 19. Bc8-d7. Fritz evaluates 19. Bc8-d7 as favoring White (.97) (18 ply) and gives the following line: 19. Bc8-d7 20. Be3-f4 Qe7-b4 21. Bf4-e5 Qb4-f8.
Instead, at Black's 19th move, Fritz recommends 19. Qe7-f6 20. Be4-c2 Bc8-d7 21. Be3-g5 Qf6-d6 22. Qg4-h4 Re8xe1 23. Rf1xe1 f7-f6 24. Bg5-d2 Ra8-e8. Fritz evaluates this line as favoring White by (.55) (18 ply).
Maroczy played a weak opening, but with Halprin's mistake at move 12, Maroczy had opportunites to save the game. Even as late as move 19, Maroczy could probably have held the position, if he had played 19. Qe7-f6.