Rafael Nadal struck a complicated balance between safety and risk to beat big-serving Reilly Opelka at Indian Wells

WATCH: Nadal defeats Opelka to reach Indian Wells quarterfinals

How did Rafael Nadal negotiate his way through two tiebreakers against a 7-foot opponent hitting 140-m.p.h. serves and 100-m.p.h. forehands?

At first, when he was asked this question on Wednesday, he claimed he had no idea.

“I can’t tell you,” he said. “I can create a story, but honestly I don’t have a secret or thing that I am sure that can work.”

Then Rafa preceded to tell us, in pretty thorough detail, what he tried to do in his 7-6 (3), 7-6 (5) win over Reilly Opelka at Indian Wells.

He tried “to play from good positions.” He tried to get a lot of first serves in, “because then if you start to miss first serves, you open the door for him to go for a big return.”

He tried “to find the right balance between not playing too aggressive, because then you have risk of mistakes, and not playing too defensive, because you know he has a great forehand.”

Finally, Rafa summed it up this way:

“It’s about trying to hit balls that you don’t take a lot of risks, but at the same time don’t allow him to go in and go for the shot,” Nadal said. “Is trying to find the right balance between these things.”

We often hear that athletes try not to think when they’re performing, because thoughts get in the way of actions. Nadal’s explanation above shows that this obviously isn’t always true for him, and that tennis isn’t always the simple game we’re told it is. Judging by what he said, a lot of thought went into each shot against Opelka, about exactly how much risk to take, about where to try to position himself, about when to get aggressive and when to stay safe.

On the surface, in a match against a servebot like Opelka, very little happens, and there doesn’t appear to be much pressure on any given point. There were two breaks in this match, and just one break point in the first set. But that means the pressure not to get broken is immense. There’s a weight on every shot that doesn’t exist in a normal match.

Nadal played “10 meters” behind the baseline to return serve, he said with a laugh. Yet there was still little he could do to counter Opelka’s serve. The match came down to just a few shots, none of which were especially spectacular.

• At 3-3 in the first-set tiebreaker, Nadal hit a good forehand pass. At 4-3, he improvised a backhand slice return that landed deep, handcuffed Opelka, and gave him the mini-break.
• In the second set, when he was down a break at 2-4, Nadal sliced a backhand a millimeter over the net that Opelka couldn’t handle; that put him up 0-30 and led to the crucial break back.
• And then, in the third-set tiebreaker, Rafa moved forward twice at crucial moments: One to hit a crosscourt forehand that put him up 4-1, and once to hit a crosscourt backhand at match point that clinched the victory.

“I just feel that it’s important, in my opinion, to know yourself,” said Nadal, who admitted to feeling some pain in his bad foot, “to know what’s the things that you have more control about, and in the pressure moments play with these shots that you feel more confident, no?”

Sometimes thinking isn’t the worst thing an athlete can do. But it only works if you can put your plan into action. Nadal, who is now 18-0 on the season, did both today, in a quietly, thoughtfully, masterful performance.