It may just be a passing thing, but I noticed that Karpov seems to really like strangling his opponents on the a-file. I'll start the collection with the famous Unzicker game and add more as I encounter them...
My favorite game, ever. Karpov vs Unzicker, 1974 (C98) Ruy Lopez, Closed, Chigorin, 44 moves, 1-0
Well, threatens to exploit the a-file... Petrosian vs Karpov, 1975 (E17) Queen's Indian, 32 moves, 1/2-1/2
Kibitzing
