1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. b1c3  3... f8b4  4. e2e3  4... e8g8  5. f1d3  5... c7c5  6. g1e2  6... d7d5  7. a2a3  7... b4c3  8. b2c3  8... d5c4  9. d3c4  9... d8c7 One of Nimzo-Indian tabias. 10. c4a2 This is  Carlsen's preferred choice.