Fighting for the control over the d5  square with a novelty.
1. e2e4  1... e7e5  2. g1f3  2... g8f6 The Petroff defense is an important part of  Mamedyarov's opening repertoire. Still, it feels somewhat unusual. 3. f3e5  3... d7d6  4. e5f3  4... f6e4  5. d2d4  5... d6d5  6. f1d3  6... f8d6  7. e1g1  7... e8g8  8. c2c4  8... c7c6  9. d1b3  9... d5c4 Quite a fresh try. 10. d3c4 [#]