Correct answer: Bb11...f4/Nf4 2.Nc3# 1...N:d5 2.Rc4# 1.Rc3?? (2.Re3#) 1...N:d5 2.Rc4# but 1...f4! 1.Bc4?? (2.Bd3#) 1...Nf4 2.Nc3# but 1...