The first  major thought by Black.
1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. g1f3  3... d7d5  4. b1c3  4... f8b4  5. c4d5  5... e6d5  6. c1f4 A relatively  rare move. 6... e8g8  7. e2e3  7... c8f5  8. d1b3  8... b8c6  9. f4g5  9... a7a5  10. g5f6  10... d8f6 