Preparing a quick f2-f4 in the spirit of the Rossolimo line.
1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. b1c3  3... g8f6  4. f1b5  4... f8d6 A fighting move. Caruana avoids the many theoritecial drawish lines. 5. d2d3  5... e8g8  6. e1g1  6... h7h6 