context: 1. e2e4  1... e7e5  2. f1c4  2... g8f6  3. d2d3  3... c7c6  4. g1f3  4... d7d5  5. c4b3  5... a7a5  6. a2a4  6... f8b4  7. c2c3  7... b4d6  8. e4d5  8... c6d5  9. c1g5  9... c8e6  10. b1a3 This is the idea behind ​​White's play. The knight finds a good square on b5.