1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. b1c3  3... f8b4  4. d1c2  4... e8g8  5. e2e4  5... d7d5  6. e4e5  6... f6e4  7. f1d3  7... c7c5  8. g1f3 An extremely sharp Nimzo-Indian line, the favorable choice of  Mamedyarov. 8... c5d4  9. f3d4  9... b8d7  10. c1f4  10... d8h4  11. g2g3  11... h4h5  12. h2h4  Vallejo's choice. The Spanish GM won a couple of games with this pawn  sacrifice. 12... d7e5  13. d3e2  13... e5g4  14. e2g4  14... h5g4 All of this is very forcing, and  both players definitely knew what they were doing. 15. f2f3  15... g4h5  16. g3g4  16... h5g6 