1. d2d4  1... g8f6  2. g1f3  2... d7d5  3. c1f4  3... e7e6  4. e2e3  4... f8d6  5. b1d2  5... d6f4  6. e3f4  6... d8d6  7. g2g3  7... b7b6 It is useful to trade the idle black bishop. 8. c2c3  8... e8g8 