Preparing Reb1 and b3-b4 in order to clear the b-file towards the target on b7.

Please note that the immediate 1.Rab1? would have failed to 1...a5! , closing the queenside.
While 1.Rh1+?! Kg8 followed by ...f7-f6 isn't at all productive for White.

Karpov is not distracted by the g5-pawn, but sticks to his plan.

Since 3...cxb4 4.Rxb4 is hopeless for Black, Spassky tries a counterattack.

4.exf5?! e4 5.Bd2 exf3+ 6.Bxf3 gxf5 , when the connected pawns and the strong bishop on g7 yield Black some slight compensation for the piece.

The d6-pawn proves to be doomed.

7...Kg8 8.Rxd6 Bxg5 9.Rxg6+ +-

With a decisive advantage.

Preparing ...Qe8-a8 in order to seize the long diagonal.

Thanks to the mating motif the knight doesn't need to retreat.

5.Qxd3 Rxc3! , again exploiting the mating motif.