Black has many candidate moves and enjoys near-equality with them.
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  5... h7h6 [%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. 6. c1f4  6... g8f6  7. e2e3  7... f8d6  8. f4e5 [%c_effect e5;square;e5;type;Interesting;persistent;true] An interesting idea: instead of exchanging bishops, White places it on e5 and waits for Black to capture it in order to place the knight or a pawn on that square. 8... c7c6  9. f1d3  9... e8g8  10. h2h3  10... f8e8  11. e1g1  11... d6e5  12. f3e5 The most natural and conventional capture, but I should mention that taking with the pawn has interesting practical value. It has never been tried before and sharpens the game. Black needs to defend accurately. 12... c6c5  13. a2a4 [%c_effect a4;square;a4;type;Interesting;persistent;true] A good prophylactic move to prevent the move ...b7-b5. 13... c5d4  14. e3d4 