A conditional retrograde analysis problem Here is the problem-find a chess game that begins with 1. e4 and ends on the fifth move with knight takes rook mate, which determines who gives the mate.
This is a famous puzzle. For additional information and its history, see this nice article on ChessBase.
The solution is as follows:


   1.e4 Nf6 2.f3 Nxe4 3.Qe2 Ng3 4.Qxe7+ Qxe7+ 5.Kf2 Nxh1#