Actually i think outdoor tennis is not real tennis - with wind like USO or playing in very hot temperature, it is more about who is more fitter will survive - yes adapting to conditions is part of tennis, but i like much more indoor tennis, wich clean conditions, where players with weapons and talented players are benefiting.
Rafa is one of very few players - actually can´t think now of anybody else in top that benefits from outdoor conditions, while is weaker indoors- while most other players are better indoors - with their serve working better, hitting cleaner means can play more agressive and so on
Rafa plays with topspin that allows him to play well in outdoor windy conditions, he is extremely fit and physically superior to most of the tour so can ,,outbattle,, them in heat-hot weather
+ his insande deffense is bettet outdoor with ,non-clean, conditions than indoors whan with no wind anybody has it easier to hit through him.
really can´t think of anybody else right now who benefits so much from outdoor elements in tennis like Rafa
If i give it in % than you have something like this
indoor tennis - 100% your potential you can play there
outdoor tennis - with wind, heat and other elements - many players must play safer, are more tired in heat and soon - can play maybe 60-70% of their potential, because are limited by outdoor conditions, but Rafa with his topspin + stamina can play maybe 90% of his tennis