I think I've learned a lot, not so much from Karpov, but from the people who annote his games. For some reason, he seems to be the type of player that good writers can use to make excellent points. Piece positioning for example. Also the above mentioned "How Karpov Wins" show that he is a very practical player in the sense that, if he is in a position that many Grandmasters would agree to a draw, he plays on, believing, mostly correctly, that he is the better player and that, sooner or later, the other guy will crack under pressure and Karpov will come out on top. Chessrube, I would be interested in what you, or anyone thinks of the book you have.
I have the new book called Strategic Wins, Making of a Champion volume 1. I really like it. It starts out with Karpov about 10. I skipped over the real early games started out looking at 1966 onward. I'm a big fan of Karpov and wanted to study his games to improve mine so I asked for suggestions and got plenty. Thanks to all.
When you say Grandmaster, do you mean "Grandmaster that was better than Petrosian", or "Grandmaster that has an axe to grind with Petrosian"?