Source: by Karl Fabel & was reprinted in Martin Gardner's New Mathematical Diversions from Scientific American (pub. Simon & Schuster), ch.19, p.223
Another commonly seen solution to this sort of problem:
White can legally resign.
I suspect the trick is, as with so many chess puzzles, that:
we are looking at the board the wrong way.
In this case, there are several possible moves:
Actually, I think there's no move that can force mate, if this is the case, because now the pawns are 'blocking' the wrong squares.
protected by Beastly Gerbil May 27 '17 at 11:52
Thank you for your interest in this question.
Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count).
Would you like to answer one of these unanswered questions instead?