Federer/Nadal - Some differences in preparation. Very similar contact point and follow through.
Grips: Eastern slightly toward the Semiwestern/Semiwestern.
Lendl/Federer - Rather different preparation, contact point and follow hrough.
Grips: Eastern/Eastern more clockwise rotated.
Lendl/Nadal - Quite opposite preparation. Very different contact point and follow through.
Grips: Eastern/Semiwestern.