context: 1. d2d4  1... d7d5  2. g1f3  2... c7c5  3. c2c4  3... c5d4 An interesting position and not well-known at amateur level. It's not easy to demonstrate an advantage for White in this opening. 4. c4d5  4... g8f6  5. f3d4  5... f6d5  6. e2e4  6... d5f6  7. f1b5  7... c8d7  8. b1c3  8... e7e5 The most accurate. 9. b5d7  9... d8d7  10. d4f5  10... d7d1  11. e1d1  11... b8c6  12. c1g5 The most natural attempt. 12... f6g4  13. d1e2  13... f7f6  14. g5h4  14... h7h5  15. f2f3 