1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. b1c3  3... f8b4  4. d1c2 A must-win situation for Yu. He  needs to choose as complex lines as possible. 4... e8g8  5. e2e4  5... d7d5  6. e4e5  6... f6e4  7. a2a3  7... b4c3  8. b2c3 