Just for the fun of it: i will join the conversation. the higher your level the better strategy you need specially when you have a very glaring weakness. knowing your strength and weakness and taking a gambit is a strategy. federer's BH became a liability when rafa started to dominate, roddick,s ground game started to be a liability when federer footworks showed that power is not everything . Before i get out of topic, here is a strategy for you. federer is a stubborn mule but ever since he had annacone they noticed the rafa's backhand is starting to become a weakness. due to federers hard headedness he tired his best to out hit rafa with his forehand therefore committing errors. since annacone came to his corner you will notice that fed started to hit to rafa's backhand which is showing some results. Nole did the same thing. attacked rafa's backhand.
Also in australian open 2009, when roger knew that andy murray was against him in the finals he had a bunch of tapes to watch the guy play in australia. it's a lot of nonsense that i typed but strategy is very important specially the higher you are.