
Solution

1. Nc7+ Bxc7 2. Qc6+ Kxa7 3. Ra1+ Kb8 4. Ra8# (or Qa8#)
Note how white uses the tempo-move, Nc7+, to clear the way for the queen, Qc6+.
1. Nc7+ Bxc7 2. Qc6+ Kxa7 3. Ra1+ Kb8 4. Ra8# (or Qa8#)
Note how white uses the tempo-move, Nc7+, to clear the way for the queen, Qc6+.