The most consistent choice.

By attacking f2 Black interferes with the plan of Rdg1 and g4-g5.

A less active defence permits 5 f3 with central activity.

Preparing Bc3 with a promising attack.

An excellent measure of restriction, which takes the e4-square away from several black pieces, and soon d5 as well.

1...Nf5 2.Qc3 Bb7 3.e4 , keeping the advantage.

Fixing a target on a7. We can also notice that the bishop on a8 has turned into a very passive piece.

This leads to new weaknesses, but Black was short of constructive ideas.

Now White manages to swap the enemy's active queen. Preferable was 6...Nxf5 7.Qc3 with a clear, though not decisive advantage – Kasparov.

White later realized his extra pawn.