Test your chess: Reitstein problem 159
White to play and win
Today for a change, I also give the position as in Reitstein's book, together with his commentary.
Hangelbroek played 1 Bd2! here, setting a subtle trap into which Donnellty fell. After 1…Bf3 2 Bf4 Be2 3 Re2 Black had seen that 3…Nd4 would win for him. That is why he chose not to move his queen away after 1 Bd2. Why was 1…Bf3 a serious mistake?
P Hangelbroek v BP Donnelly 1967
Solution
One of the problems inherent in puzzle books is that the rubric can give clues. Here, it was obvious to me that there must be a surprise move, and 2 Qe8+! came immediately to mind: and it is not hard to see that it is decisive. In a game, the standard Purdy technique of considering all biffs would have shown it too.

