1. e2e4  1... e7e5  2. g1f3  2... g8f6 Caruana switches to the Petroff after the painful loss that he suffered in Norway earlier this year. 3. b1c3 Nakamura prefers to stay clear of the main lines. Just like in Norway, he has prepared something nasty for his opponent, but this time in the Four Knights. 3... b8c6  4. d2d4  4... e5d4  5. f3d4  5... f8b4  6. d4c6  6... b7c6  7. f1d3  7... d7d5  8. e4d5  8... e8g8 Considered to be the most accurate move-order nowadays. 9. e1g1  9... c6d5  10. h2h3  10... c8e6  11. d1f3  11... c7c5 Logical and obvious play. So far both players are playing fast and confidently. 12. f1d1 But now Caruana needs to take some time on the clock. How to lower the central tension $2 12... b4c3 With trades, Black decided. 13. b2c3  13... d8a5 This is Caruana's idea, avoiding the pin. 14. c1g5 Nevertheless. 14... f6e4  15. d3e4 