This week’s game is a cautionary example of when the black plan with b7-b5 can go wrong. As we mentioned last week, a critical factor in this plan’s success is usually that he have a strong grip on e4. White usually tries to react to b5 by breaking in the centre with e3-e4, which, if successful, threatens to undermine the black structure.
The following is a classic example. Spassky’s b5 is misjudged, and further subsequent inaccuracies enable Karpov to give a perfect demonstration of the white strategy.