[%c_effect h6;square;h6;type;Interesting;persistent;true] Another subtle pawn move with the idea of preventing the development of White's bishops. Super-GMs are above the common laws of opening play. Carlsen has played this system a few times already.
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  5. b1c3 