1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. b1c3  3... f8b4  4. e2e3  4... e8g8  5. f1d3  5... d7d5  6. c4d5  6... e6d5  7. a2a3  7... b4d6  8. d1c2 Both players are entering one of the most complex structures, a Carlsbad with a white dark-squared bishop behind the pawn chain. 8... a7a6  9. g1e2  9... f8e8  10. e1g1 10.0-0 is the recent fashion according to Megabase.