1. d2d4  1... d7d5  2. c2c4  2... e7e6  3. g1f3  3... a7a6 This cunning little move threatens to capture on c4 followed by the protection of the pawn with ...b7-b5. White usually captures on d5, which in some ways is desirable for Black since the light-squared bishop can be developed. The big question is whether it's worth \"wasting\" a tempo with ...a6 for this, although even this move is useful in a number of situations. 4. c4d5  4... e6d5 