Mate in 4

The tempting 1.Ke7?, eyeing 2.Nd4# and 2.Nxa7#, runs into the sharp counter 1...Re3+!

A more convincing attempt is 1.e4?, setting up 2.Bd5#. Now, after 1...fxe4, White plays 2.Ke7, rendering Black helpless against 3.Nxa7# and 3.Nd4#. But here, 1...Bg8!—intending Rh7+ in response to Ke7—derails White’s attack.

To bypass these defensive resources, White must first execute a foreplan. The key move is the subtle 1.c3!, introducing the threat of 2.Nxa7+ Kxd6 3.Qxb6+ Ke5 4.Qd4#. Black's only defensive try is 1...f4, hoping to create an escape route. However, White now strikes with 2.e4!, threatening 3.Bd5#. If 2...fxe3 ep., then 3.Ke7! makes 4.Nd4# or 4.Nxa7# unavoidable. If 2...Bg8, then 3.Kxg8 seals the deal, as 4.Bd5# is unstoppable.

A fine example of a logical moremover.