10. Kasparov – Karpov (1986 game 14) – 18.axb5
Coming off the heels of a hotly contested 1985 match Karpov was once again prepared to meet Kasparov in a championship match. The two had been discussing the various nuances of the Zaitsev Ruy Lopez when Kasparov uncorked what came to become one of the main lines in the Zaitsev. There really wasn’t much theory related to these lines in fact the earliest games in the chessgames database in this particular system that I could find was a game played between Pinter and (who else?) Zaitsev in 1975.
To date this line has been played in 43 games and 29 GM games scoring 34.9% for white in the big database.