1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1b5  3... g8f6  4. e1g1  4... f6e4  5. f1e1  5... e4d6  6. f3e5  6... f8e7  7. b5f1  7... c6e5  8. e1e5  8... e8g8  9. d2d4  9... e7f6  10. e5e1  10... f8e8  11. c1f4  11... e8e1  12. d1e1  12... f6d4 A dangerous move, which is not the most popular. In exchange for the pawn White gets a superior pawn structure and it will be difficult for Black to finish development. Carlsen has some experience in this position, but all his previous opponents preferred the main move, 12...Ne8. The fact that Carlsen didn't win any of those games says a lot about the solidity of Black's position.