Breaking news, everybody: First serves are better than second serves!
That’s what I learned, anyway, from the latest article in the “Infosys ATP Beyond the Numbers” series:
When you average out the Top 10 players in the 2015 season, they are saving break points 72 per cent of the time when making a first serve. On average, that drops to 53 per cent with second serves. That 19 per cent difference is one of the most important, hidden metrics in our sport.
Is the difference between first and second serves “important?” Definitely. Is it in any way “hidden?” Not so much.
The melodramatic phrasing here suggests that break points are different from regular points, perhaps with a much larger spread between first and second serve winning percentages. But no, that’s not the case.
Last year, top ten players won 75.6% of first-serve points and 55.4% of second-serve points. Combined with the Infosys numbers–which I can’t verify, because the ATP doesn’t make the necessary raw data available–that means that top ten players win 5% less often when making a first serve on break point, and 5% less often when missing their first serve on break point.
At the risk of belaboring this: When it comes to the importance of making your first serve, break points are no different than other points.
Even that 5% difference is less meaningful that it looks. Break points don’t occur at random–better opponents generate more break opportunities. If you play two matches, one against Novak Djokovic and one against Jerzy Janowicz, you’re likely to face far more break points against Novak than against Jerzy … and of course, you’re less likely to win them.
Pundits tend to focus on break points, and in part, they are right to do so, because this small subset of points have an outsized effect on match outcomes. However, because of the small sample, it’s easy–and far too common–to read too much into break point results. My research has repeatedly shown that, once you control for opponent quality, most players win break points about as often as they do non-break points.
The ATP is sitting on a wealth of information. If we’re going to learn anything meaningful when they go “beyond the numbers,” it would be nice if they took advantage of more of their data and offered up more sophisticated analysis.