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 