As America's favorite single-elimination tournament began to take shape Sunday, there was another one wrapping up at about the same time: the BNP Paribas Open at Indian Wells, the biggest tennis tournament outside of the Grand Slams according to prize money.
Everyone watched Greg Gumbel flub announcing Miami's seed during the selection show; no one watched Maria Sharapova dominate Caroline Wozniacki or Rafael Nadal's return to form. Everyone can probably name five different reasons why tennis doesn't grab the country's attention like other sports do, but to me, that question looms largest during March Madness. Tennis tournaments have so much in common with the NCAA tournament (similar format, compelling storylines, great matchups), so why don't they get even a tenth of the love that college basketball does?
Indian Wells even happens during the same time period, with all the marquee names you'll see at the French Open in two months (with two notable exceptions): you don't even have to wake up early to watch! So how come no one does?
Like I said, there are probably a lot of legitimate reasons, but the biggest difference that sticks out between Grand Slams and March Madness is what drives the "Madness" part: upsets. All four No. 1 seeds have only made the Final Four in basketball once; it seems the Big Four of men's tennis have a cakewalk to the later rounds of every Grand Slam. Whether or not tennis would be more engaging and entertaining if there were more early upsets -- and if there's anything that can or should be done to change that -- is a debate I think is worth having in full. And that starts with asking this: Exactly how top-heavy is tennis as a sport?
You could answer that question with a bunch of numbers in the abstract, but I think it's far more illustrative to show how top-heavy tennis is compared to a sport for which we have some intuitive sense of team strengths: college basketball. Let's compare the BNP Paribas Open field to that of the NCAA Tournament. In order to make this comparison, I used an adapted version of Advanced Baseline to produce a set of college basketball rankings using all data through March 17th (for other examples of systems that rank college basketball teams this way, see here and here).
If we normalize both these basketball rankings and the Advanced Baseline men's and women's rankings by dividing each player/team's ranking by the top rank in their sport, we can show how good each player/team is relative to the highest ranked player/team in their sport. This produces a roughly apples-to-apples comparison of the strength of men's tennis, women's tennis, and NCAA basketball fields, all of which can be plotted on the same graph. The graph below shows the relative depth of the Indian Wells men's field, Indian Wells women's field, and the NCAA tournament of this year. A couple modifications and clarifications:
- The Williams sisters and Li Na were included in the women's field in place of the three lowest-ranked wild card entries in order to represent the depth of a more typical, full-strength women's field.
- Each tennis player's hard-court ranking was used, not their base ranking. This skews the men's and women's graph in a surface-specific way, meaning the graph would look different for a clay tournament like the French Open.
- Indian Wells is a 96-player field, with the top 32 seeds getting a bye. In order to compare it to the NCAA field, the player rankings are used for all players remaining from the field of 64.
- The basketball field assumes the winners of the play-in games are North Carolina A&T, Long Island, Boise State, and Middle Tennessee.
(Click to enlarge the image.)
The NCAA field strength is probably what we would intuitively expect: you have about six legitimate contenders with Florida (yes, Florida) at the top left, Gonzaga not far behind, Indiana and Louisville a step below them, Duke and Kansas at the third step, and then pretty much everyone else. But for the men's tennis field, we have to use the term "contender" a little more loosely: Novak Djokovic is up there at the top left, and there's a chasm between him and Roger Federer/Andy Murray, after which it's pretty much everyone else. The women's contender field is a little more inclusive, with Victoria Azarenka at the top left, Serena Williams within striking distance, and Sharapova within striking distance of Serena. Agnieszka Radwanska and Li Na are sort of in contention at the 0.3 mark, but it's pretty much the field after that.
What's more striking about the difference and relative strengths of the contenders in each field is how far off the pace the mid-level players and teams are in tennis. In basketball, the not-quite-contenders in the left-middle range of the graph aren't too far off the mark, which is why we can expect at least one of those six contending teams to face an early-round upset from a Creighton or Wisconsin-caliber team. In the tennis fields, though, your Mona Barthels and Milos Raonics just don't seem to have a prayer of beating the contenders, which is confirmed by what we anecdotally see in most of the Grand Slams: it's very chalk-heavy in the early rounds.
I think some of this is due to natural differences between individual and team sports. In basketball, you have some element of a team being only as good as its weakest link: even the most dominant college basketball team in recent memory, 2012 Kentucky, still had to give minutes to Doron Lamb, and he was "only" a mid-second round draft pick. Individual sports, however, are far more vulnerable to domination by freakishly talented individuals, whether it's Tiger Woods, Michael Phelps, or Novak Djokovic; when there's no one else on your team, you don't have any weaker teammates you have to support, allowing you to rise to the top of your sport unconstrained.
Is this part of the appeal of sports like golf and tennis, where you can watch a single person single-handedly destroy the field for a given competition? Absolutely. But as a hypothetical, I think it's worth asking this: What are the effects of a sport becoming too top-heavy (if that's even a thing)? As an example, consider the ATP/WTA points system, which allocates rankings points based on tournament progression, heavily weighted towards Grand Slam results. What determines your ability to gain in the rankings more: your actual skill level, or whether you avoided drawing one of those elite players in your section? And how would that balance of performance versus luck-of-the-draw change if that curve above was more or less steep? These are the considerations that should go into deciding whether or not tennis is "fair," and it starts with a solid understanding of just how top-heavy the talent pool really is.