Tonight was one of those perfect examples of why Nadal has had the EXTENT of success that he has, beating players in the Top 10, Top 20, and Top 30 as much as he has. It most certainly is not because of superior shotmaking ability (today's match showed that beyond a shadow of a doubt) or superior talent for actually playing the game of tennis, but because of his immense stamina and the mental profile of persistence, constany, and consistency that he possesses. When Kohlschreiber had his legs under him in the first set and was fully executing his offense (and this goes for later parts of the match too), his shots were simply too much for Nadal to handle. Yes, Kohlschreiber's serve helped, but he also owned Nadal from the baseline quite a bit tonight.
How many matches has Nadal won over the course of his career by simply out-lasting opponents? The other guy comes out on fire and shows he has too much game for Nadal, but then Nadal goes into gnat-mode and just chases everything down, mixing in some opportunistic offense and keeping the unforced errors low and the double faults nonexistent. Then the other guy eventually cracks with a couple errors and Nadal - with his immense stamina - is ready to play for another six hours. He has done this to Federer, Del Potro, Nalbandian, Gulbis, Murray, Kohlschreiber tonight, and many others.
There are three particular things that stood out to me in this match:
1) All of the hilarious points when Kohlschreiber simply dominated Nadal from the back of the court and hit clean winners.
2) How Nadal responded physically and mentally after losing the first game of the third set when it went to deuce about ten times on Kohlschreiber's serve. He came back as primed physically and engaged mentally as one could be. This is what I mean about immense stamina and mental persistence. These are clearly the attributes that separate Nadal more than actual tennis-playing ability, because Kohlschreiber had much more in the way of great baseline winners today. Nadal had his share, but Kohlschreiber was superior in that regard.
3) The point at 30-40 in the first game of the fourth set when Kohlschreiber missed the overhead. That point is an excellent snapshot of Nadal's career, in a very significant (but not total) sense. He is scrambling, running, chasing balls down, forcing one more shot - and then the other guy misses the shot. Nadal wins the point because the other guy made an error, not because he did anything special with it. Kohlschreiber dictated, Nadal was the ultimate gnat, and Kohlschreiber did not finish the final shot off. Nadal's (extent of) success in a nutshell right there. Take a look at the Federer series on clay.
In the end, Nadal wins the high-profile matches at the rate he does more so because of immense stamina and the psychological profile of extreme persistence, constancy, and consistency far, far, far, far more than his game being superior in terms of shotmaking (which it isn't). I don't see how anyone can object to that after watching the match tonight.