I'm a mixed fan of Mednis (I don't like his repertoire books, like "From the opening to the endgame," but his endgame books are superb), but this is an exceptional book. He breaks down the elements of Karpov's style both statistically and analytically, and does a good job of showing Karpov's approach to the game. Karpov's style may not appeal to everyone (not terribly exciting), but he always plays to win and is notoriously difficult to beat. Mednis shows the openings he plays, the middlegames he prefers, and his preference for clear endgames over advantageous middlegames. Most useful for ELO 1600+ players.