1. f2f4 The most natural and also the best move, opening the diagonal for the bishop and attacking the a7-pawn. No wonder it was played in all four games of the round. 1... a8b6  2. a1b3  2... f7f5  3. e2e4 Judging by the other games, this is a kind of \"theoretical line\" from this starting position. The computer doesn't approve of this move. 3... f5e4  4. e1e4  4... g8d5 A logical move, improving the position of the bishop and leaving room for the queen. However, the bishop can be attacked by the knight after Ne3. 5. e4e1 