1. e2e4  1... e7e5  2. g1f3  2... g8f6 Caruana played the Petroff in several games during the match. This is one of the most reliable defenses for Black and it's no wonder that many elite players are happy playing it. 3. f3e5  3... d7d6  4. e5f3  4... f6e4  5. b1c3 This line has a good reputation. Caruana has great experience in it, having played this position with both White and Black, including a game in the World Championship match against Carlsen. 5... e4c3  6. d2c3  6... f8e7  7. f1d3  7... e8g8  8. e1g1  8... b8d7  9. f1e1  9... d7c5  10. c1f4 If it had been a game at normal time control, Erigaisi would probably have moved the d3-bishop to avoid the exchange. In a bullet game, this is just a minor detail. Or is it not $2 As we will see, the pair of bishops was crucial to Caruana's victory. 10... c5d3 