A great lesson position! Szabo was White against Milner-Barry in the late 30s and found a great move: 1.Qc3!! You have been given the first move. Now analyze the possible defenses by Black and what you would do to meet them. Szabo had to do that before he chose that move.
1.Qc3 Qg6 [1...Bf6 2.Rae1 Qb5 3.Qc4 Qd7 4.Ne7+ Bxe7 5.Rxe7 Rxe7 6.Rxe7 Rxc4 (6...Qf5 7.g4 b5 8.Qc3 b4 9.Qc4 Qb1+ 10.Kg2 Rf8 11.Rxa7 Qxb2 12.Rb7 Qc3 13.Rxb4 Qxc4 14.Rxc4 Ra8 15.a4 with an endgame advantage) 7.Rxd7 Kf8 8.Rxb7; 1...f6 2.Ne7+ Kh8 3.Nxc8 Qd8 4.Rxe8+ Qxe8 5.Re1 with a win; 1...Qf6 2.Rae1 wins] 2.Rae1 Kf8 3.Qc5+ Black Resigns. The back rank threats throughout are pleasingly instructive.