That is because Nadal is a natural right-hander, which adds heft to his two-handed backhand.

“If he is taken out wide on the backhand, he uses a lot of right arm to be able to muscle that ball into play,” Cahill said. “No one else from that far back in the court can throw the ball up with that amount of spin and give it enough hang time to make it uncomfortable for the opponent to put away that first ball. It’s just difficult to do that.”

The discomfort for the opponent is not only due to Nadal’s heavy strokes. It comes from knowing that putting the ball past him when he is healthy and hitting passing shots with precision and flair remains one of the game’s great challenges.

“When he’s confident, really confident and playing well, and he does this on clay, too, he’ll start the point from a deep position and then you watch where he goes after he hits the return,” Annacone said. “He gets up right behind the baseline and then tries to dictate. If he stays back there after the return, that’s when he’s unconfident and a little bit vulnerable.”

Nadal’s extreme variations in return position — either tight to the baseline or far back near the ticket holders — also create doubt and confusion in his opponents.

Still, a lesser player and athlete would have paid too high a price for the deep positioning, and there is still an occasional tax on the tactic: Gilles Müller, in his upset of Nadal at Wimbledon last year, was particularly effective in opening up attacking opportunities by serving wide to Nadal’s backhand side in the deuce court.

Roger Federer has used his own precision serving to shift the momentum of his once-lopsided rivalry with Nadal. Last year’s final in Shanghai, which has one of the quickest surfaces on the ATP Tour, was a case in point. Nadal could not manage to get a single break point on Federer’s serve and lost, 6-4, 6-3.

“Roger is one of the greatest strategic servers who has ever played,” said Annacone, Federer’s former coach. “You give him that space, particularly on a fast court, and that’s a problem. And that’s why Novak Djokovic is harder for Roger to serve against than Rafa, because he doesn’t give him space. He’s so long. He can stay up on the baseline, and if Roger doesn’t hit his targets, Novak will punish him.”