Heading for f4(-d3).

Preventing the ...Nf4-d3 maneuver in advance, but now Black reverts to his first plan with great effect.
4.g3 was better, with just a slight disadvantage after g6 followed by ...Bg7 – Serper.

Fixing the queenside and enabling ...Bb5.

Black has a more pleasant game.

Using some minor tactics White manages to advance his kingside pawn majority.

1...f6? 2.Qxa7+-

A clever tactical resource.

4...Qxe4 5.Bxe4 Nc4 6.Kf2 Kf8 7.Bd5 Nd6 8.e4+/-

This converts the e-pawn into a strong passed pawn.

6...Ne7 would be better.