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 