1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. b1c3  3... f8b4  4. d1c2  4... e8g8  5. a2a3  5... b4c3  6. c2c3  6... d7d5  7. c1g5  7... h7h6 7...dxc3 and 7...c5 are popular alternatives. 8. g5f6  8... d8f6  9. g1f3  9... d5c4  10. c3c4  10... b8c6  11. c4c3 This move is necessary to fight the e6-e5 advance. All this is still theory.