Temporarily shuts the  diagonal for the bishop, but Yip correctly decided to keep the bishop  alive.
1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1b5  3... a7a6  4. b5a4  4... g7g6  5. d2d4  5... e5d4  6. c2c3  6... f8g7  7. c3d4  7... b7b5  8. a4b3  8... g8e7  9. d4d5  9... c6a5  10. c1d2  10... a5b3  11. d1b3  11... c7c5  12. d2c3 