comment: There are many alternatives. The opening theory in each position of Freestyle allows for many hours of discoveries.
context: 1. a1b3 Interestingly, in this starting position the weakest square is a2-a7, which has no protection. In the conventional chess position the weakest point is f2-f7, which at least has the protection of the king. The move 1.f4 therefore creates an immediate threat right after the first move. 1.Nb3 brings the knight into play and protects the weakness on a2. This move was played in all the games of the round.