context: 1. f2f4 The most natural move, opening the diagonal for the queen and attacking a7. 1... a8b6 A peculiarity of FreeStyle Chess: it's possible that Black's first move is already clearly better than the alternatives, as is the case here. 2. b1c3 Black has to be careful with the move Nc3-b5, attacking a7 and c7. 2... f7f5 Now White shouldn't play 3.Nb5 as Black can take on a2. 3. a1b3  3... b8a6 Caruana keeps the c7-pawn protected.