1. g1f3  1... d7d5  2. e2e3  2... c7c5  3. b2b3 A very popular line in blitz. 3... b8c6  4. f1b5  4... c8d7  5. c1b2  5... e7e6  6. c2c4  6... g8e7  7. c4d5  7... e7d5  8. e1g1  8... a7a6  9. b5e2 [#] 9... f7f6 An  ambitious novelty. Caruana defends the pawn and wants to complete the  development in the most optimal way, putting the dark-squared bishop on  the b8-h2 diagonal. 10. d2d4 The most ambitious strike. So needs to build his initiative  while his opponent has has the king in the center. 10... f8e7  11. e3e4 Consistent, but it transpires that Black has enough  tactical resources here. 11... d5f4  12. d4d5  12... c6d4 That is the point. White has problem with his  Be2. 13. f3d4 