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  8... c7c5  9. c1b2  9... b8c6  10. f1d3 