By hitting the a7-pawn and hampering ...g7-g6, White provokes the undesirable ...c6-c5.

1...a5 2.0-0-0 leaves Black without reasonable moves.

Now a weak square has appeared on d5.

With a sound extra pawn, White soon won.

By attacking the e2-pawn Black provokes a concession from White.

After 2.f3?! Be6 a weak square appears on e3, and the fianchettoed bishop becomes severely restricted.

The exchange on d4 has yielded Black a semi-open file and reduced White's dynamic potential.

The active 5.e4 was preferable, e.g. 5...dxe3 6.Nfxe3 Nxe3 7.fxe3 Rcd8 8.Ra3 with just a slight disadvantage – Botvinnik.

Black starts working towards the target on e2.