Agree for Federer, but imagine what could have been Nadal's 2011 season without Djokovic...
He was still very good, but the fact is that Djokovic has improved his level in 2011, and a lot.
nole always has the potencial to defeat nadal in harcourts , the same nadal say that even pre-2011 when djokovic playing good against him in harcourts he has all the chances.
the problem with that djokovic is that like federer , he attacking all the time and nadal`s defense provoques the desesperation and mistake of nole , in 2011 nole started to use much more his physicall condition and patience and because nole it`s much more talented player and shotmaker than nadal from the baseline , he obtains the perfect combo to frustrate nadal: a wall from the baseline with much more patience and better shotmaker.
federer has the tennis but no the reguarity from the baseline and physicall conditions of nole , and one handed backhand