[Archived from: The Sports Economist, 25 January 2013]
As the Australian Open approaches the business end, this year’s installment has developed a palpable sense of familiarity of recent years about it. Each of the top four seeded men made the semi-finals, and it’s hard to escape the feeling that fourth-ranked Rafael Nadal would have been in the place of his compatriot David Ferrer if he were present. And so we have the familiar trio of Andy Murray, Roger Federer and Novak Djokovic left standing.
The story in the women’s singles has been notably different, and not just to this stage. There were a sprinkling of upsets in the first week – earlier in the tournament only 3 of the top 16 men’s seeds were eliminated before the fourth round, compared to 7 casualties from the top 16 seeded women.
In comparing the sexes, it is worth reflecting how the modern era of tennis is arguably an unusual one in terms of the relative competitiveness in both the men’s and women’s games.
The current prevailing wisdom among occasional observers of the sport is that men’s tennis is highly predictable – at least until the semis where the fab four seem to meet more often than not, and that now, it is the women’s draw that offers a far more balanced and interesting proposition.
Historically, this is unusual – but long-passed are the successive eras of Margaret Court, Chris Evert/Martina Navratilova and Steffi Graf/Monica Seles. Back then, you could almost bet your vital bodily organs that any Grand Slam trophy would end up safely in one of only two or three possible pairs of female hands, even before a ball was served in anger. Meanwhile, the four majors seemed to be far more contestable on the male-side of the draw.
Things began to change in the early-to-mid 1990s – the rise of emerging women, such as Arantxa Sánchez Vicario, Mary Pierce, Martina Hingis and Lindsay Davenport, renewed interest in the women’s game. Concurrently, the Sampras/Agassi duopoly began to hold sway, as it would for the better part of the following decade.
A short period followed in which Jennifer Capriati and the Williams sisters dominated the majors, at a time when the male duopoly loosened its grip and other men, including Lleyton Hewitt, had comparable claims to slam titles.
In the decade since, however, other women such as Justine Henin and Maria Sharapova have once again challenged at the top to produce a more open field, while the ascension of Roger Federer, since joined by the other three members of the quartet, has made the men’s game look like a closed shop.
However, this prevailing wisdom is ill-informed. Many of us will only watch a handful of games on television during the Open. Locals, even certified tennis tragics, who go to Melbourne Park will not see many televised matches in the other months of the year, let alone live overseas.
In fact, the ATP and WTA tours each involve roughly 2,500 matches each year in the top-four tournament tiers (and the season-ending championships), and only an analysis of all of these matches can tell us the complete story of the overall tour, as opposed to merely anecdotal evidence at the very apex of the talent pool.
I was motivated to find whether this conventional wisdom was indeed true over the entire tours, and so having obtained data on all matches (excluding walkovers, retirements and disqualifications), I set out to find the answer. I went back as far as 2007 – the last year in which the fab four did not quadrella the end-of year rankings (Andy Murray would join them in 2008). During this period, Serena Williams found a way to win a further eight slam titles during her post-injury renaissance, but she hasn’t had it all her own way – she has only occupied the top end-of-year ranking spot once (twice finishing outside the top five).
One simple statistic would be the percentage of matches that go to a third set. For this, we would have to exclude best-of-five set men’s matches (mostly grand slam) to circumvent an unclean comparison.
On this score, more men’s matches are competitive, with 33.8% going to a deciding set compared to 31.2% of women’s matches (31.6% if grand slam matches are excluded for closer comparability).
Another sensible statistic is the proportion of matches where the favourite was beaten, as a measure of propensity for upsets. Only matches in which all (at least three) bookmakers odds were unanimous on the favourite were analysed.
Here, slightly more women’s matches were upsets (26.8% to 26.6%), but again, best-of-three and best-of-five matches are not comparable – statistically, the underdog is less likely to beat the favourite when the match is longer.
When grand slam matches are excluded for both sexes (plus a handful of other best-of-five tour event finals), the scales again tip in favour of the men (28.1 to 27.7%). The story was similar with two other metrics I investigated, specifically the median of the log-ratio of the betting odds and the average number of games won by the loser.
It is worth noting that these differences are not statistically significant, but it dispels the prevailing wisdom that elite women’s tennis has been more competitive in recent times.
I emphasise that this result should not be taken as an endorsement of men’s tennis over women’s; rather, it warns of the ever-present danger of various stakeholder groups in sport (or any other industry for that matter) making false inferences due to extrapolating on a small number of matches (or observations) to make crude generalisations without looking at the data in its entirety.
Ultimately, however, the title odds at Melbourne Park were more open on the women’s side two weeks ago. Therefore, next time you have to decide between watching a men’s and women’s match, there are numerous factors that will determine whether or not it will be an exciting and close match, so I would advise to simply use your own discretion.