Serve-and-Pray: The Quirks of Isner’s Early Exit

The big story after Steve Johnson‘s upset of John Isner today was Isner’s unhappiness with his court assignment. Still, for those of us more interested in the game itself than in post-match carping, Johnson’s surprise victory was plenty notable.

Almost every Isner match is a serve-dominated, one-dimensional contest. This one was even more unidimensional than usual. Both players won 89% of first-serve points, a combined mark that stands as the most extreme of the season. Two players haven’t combined to win more than 89.2% of first serve points since Brisbane early last season, when Grigor Dimitrov and Milos Raonic combined for an outrageous 94.0% of first-serve points won.

The difference between Isner and Johnson–slim as it was–appears in their success rate on second-serve points. Johnson won an impressive 68% of second offerings, while Isner won only 43%. That typically doesn’t do the job–since 2010, Isner has won only eight of 36 matches when he wins fewer than 45% of second-serve points. Still, he managed to avoid clustering too many of those ineffective second serves, allowing Johnson only two break points.

As bad as that second-serve winning percentage is, it would often by sufficient when combined with that other-worldly win rate on first serves. Taken together, he won 73% of service points, which–barring particularly good or bad streaks–translates to a hold of serve in 93% of service games. That’s Isner’s hold rate for the season so far, and sure enough, it was his hold rate today, when he was broken only once in 16 tries.

While Big John often seems unbreakable, he typically loses a service game or two in every match–even on the days he wins. He’s been broken exactly once in nine hard-court matches this year, and he’s won seven of those matches.  Since 2010, he’s won 45 of the 60 matches in which his opponent broke him exactly one time–many of them thanks to his excellent tiebreak record.

But today, his opponent really was unbreakable. Compared to Johnson’s service numbers, Isner’s look positively pedestrian. Steve won 80% of service points, which–again, barring too much streakiness–translates to a hold of service in an incredible 97.8% of service games. Put another way, that’s one break of serve every eight sets or so.  (For reference, Isner’s 93% season-to-date average is best on tour, and no one topped 92% for the 2013 season.)

Johnson’s not usually that good–Isner’s indifferent return game explains much of the magnitude of these numbers. Still, it’s an extremely bad return performance by any standard. It’s only the fifth time since 2010 that Isner has won so few return points in a match he completed, and it’s only the second time this year he has failed to earn a single break point. Remarkably, that last aspect of return futility isn’t always enough to keep him out of the win column: Three times, he has won a tour-level match without earning any break points.

Today, despite the lack of break points, despite the dismal second-serve percentage, despite winning 12 fewer points than his opponent, he found himself in a third-set tiebreak, two points away from victory. Big John’s game isn’t much fun to watch–while this all transpired, I was across the grounds taking in a doubles match–but on paper, his results are endlessly fascinating.