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 