After watching Nadal's matches against Gil and Wawrinka, what I, and I am sure some of the other players - including DelPo - have observed is that the best way to play Nadal on HC is to hit high and deep to him, or what are called moonballs, frequently interspersed with short angled balls, esp. to his FH. More often than not, Nadal gets pushed well behind the baseline and then gives a short reply that you need to pounce on. This is actually something I noticed first in his semifinal with Tsonga at last year's AO. Every once in a while, especially when forced on the defensive, Tsonga, rather than just getting the ball back or going for an all-or-nothing shot, would loop it back deep with a ton of topspin, causing the ball to jump to Rafa's head+ - this gave Nadal immense problems, and virtually every such shot from Tsonga resulted in an easy reply. Murray also did a similar thing to Nadal at various points during their recent meetings, also with some success.