I came across the following puzzle on lichess (black to play):
[Event ""] [Site ""] [Date "????.??.??"] [Round ""] [White ""] [Black ""] [Result "*"] [FEN "1k5r/1pp2q2/p2p2n1/4pp2/2PPP1p1/1P2B1P1/P2Q1P2/2KR4 b - - 0 1"] 1...f4 2.dxe5 ( 2.Bxf4 exf4 ) 2...fxe3 3.Qxe3 dxe5 *
Which apparently proceeds as follows:
- ... f4
- dxe5 fxe3
f4 is clearly a good move, since both sides have triple protection on the f4 square so black always ends a piece up. What is confusing me, however, is the following move by white – dxe5. This is odd, since fex3 is a queen threat, and hence a forcing move. Stockfish, on the other hand, agrees with dxe5.
Why can white not play Bxf4, simply taking the pawn and also avoiding the queen threat?