Small sample size is typical of head-to-heads in pro tennis. Both seeding and knockout tournament designs mean that many pro players have played each other no more than a handful of times or sometimes never at all. Still, I find myself frequently surprised when I come across sparse head-to-heads between some seasoned players. It got me thinking if that reaction is even reasonable and how you might quantify how much some matchups are overdue?
If you thought Serena vs Maria was a lopsided head-to-head, you are right. But it isn’t the biggest head-to-head effect in recent WTA history.
Matchup effects are a common idea in tennis commentary. It is the thing at the heart of comments like ‘her game matches up well’ against her opponent. One way to think of a matchup effect is as a surprising head-to-head, when results go against what the overall ability of both players would have us expect. Do such effects exist? And are they substantial enough that they matter when it comes to making better predictions about tennis results?
Last week we looked at some of the biggest mismatches in the men’s game. What does the same analysis tell us about the most baffling women’s head-to-heads?
Why is it that some players seem to consistently underperform against certain opponents? And how could we measure the all-time most surprising head-to-heads in the game?