Provoking the e4-e5 advance in order to install a blockade on d5.

The simplest choice, creating a new weakness.

Preparing ...Re7 with a more efficient defence of the f7-pawn.

Parrying the threat of 9 Qh5. Thanks to his strong knight and the weak pawns on d4 and g3, Black has a more comfortable game.

Preparing a blockade by Nf3 and Bd4, even at the cost of a pawn.

3...Qxb3? 4.Qh4! with a far improved version of the game

This move is not just threatening a rook, but also enabling the tactical idea of e6 and Qf6.

By now the powerful dark square blockade and the exposed black king outweigh the pawn.

By advancing the e-pawn before it is blocked by Nc3-e4, Black frees the a1-h8 diagonal and the e-file for an attack on the white king.