The Chess Mind

Browsing a new games collection, I came across the following comment:

There are innumerable examples with this line [the Zaitsev Variation of the Ruy Lopez]; everyone knows the famous games from the world championship matches between Kasparov and Karpov.

It cannot be within the scope of these brief notes to discuss the merits of the main line in detail. The general statement must suffice that in introducing a sharp, clear-cut idea of counterplay (f7-f5 destroying white's centre) it seems to be more promising than the continuation chosen by...."

Who said it, and why is the comment noteworthy? I'll give the answer and explanation tomorrow. (Meanwhile, back to preparing for tonight's ChessBase show.)