Aussie Tennis Stars Statistically Fail to Fire at Home


My first newspaper piece for 2015 appeared in the Australian Financial Review (today, Friday 9 January), called: “Home-court advantage fading away in Australia”. It did not appear on-line, so e-mail me a request for a copy if you’re a tennis fan (even if you’re not) who wishes to read it. Alternatively, it’s on p.35 of the hard copy for those with access.

It builds on work I’ve been doing with Dr James Reade (University of Reading). The basic thrust is that home advantage on the ATP Tour was insignificant for Australian (male) tennis players over our 2003-2013 sample period, unlike most other major tennis-playing nations. These blokes had better start pulling their collective finger out!

UPDATE: They did…a bit!

Back on ‘ABC News Breakfast’


I was back on (ABC1) News Breakfast with the all-Bev team (Scott Bevan and Beverley O’Conner) for the first time in nearly 2 years. It was on 10 January (took me a while to get up online) during the Open. I was talking about home-ground advantage (or lack thereof) for Australian tennis players. Details below.


Liam Lenten interviewed on ABC1 News Breakfast about his study (with James Reade, U Reading, UK) on home-court advantage in tennis – specifically, that it is not significant for Australian players, at least for seeds. The interview was recorded during the Australian Open.

Forget ‘Fab Four’, Men’s Tennis Still More Competitive


[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.

Mixed Strategies in Challenging: Tennis Edition


[Archived from: The Sports Economist, 29 January 2012]

Played last night into early morning, the epic almost six-hour, five-set Men’s Singles Final of the 2012 Australian Open between top two seeds Novak Djokovic and Raphael Nadal will be long-remembered by tennis purists for many reasons.

For economists, however, one relatively minor incident may just stand out, if for nothing else as a game-theoretic oddity: Nadal challenged the call on his own serve [watch footage], which had been ruled in by the line judge (and not overruled by the chair umpire), ostensibly because Djokovic rifled a rapid-fire winner in return, at a not-so-critical moment in the second set…and it almost worked to earn a replay of the point for him, as Hawkeye ruled the serve to be in only by a hair’s breath.

Of amusement is how neither of the host broadcaster commentators Lleyton Hewitt nor Jim Courier  (both former world number ones) appeared to know whether this was indeed permissible under the current rules of the Challenge System, especially since the former is still a tour professional (he had bowed out in four sets to Djokovic in the fourth round). Fortunately, the chair umpire knew better, although Djokovic protested briefly on the basis that it took Nadal too long to indicate the intention to challenge, however, given the (weak in one’s opinion) standards of enforcement of time limits to indicate, the chair umpire was probably correct in allowing it.

Perhaps it worth wondering whether ITF officials and collaborators foresaw this (and other hitherto unobserved unusual scenarios) when drafting the specifics of the system, and indeed whether in light of this occurrence they will decide to ‘close the loophole’, though I’d doubt it, since there seems to be nothing fundamentally wrong with this type of challenge in principle.

Since less than half of all challenges currently are upheld, if there is a reform worth considering, it would be the limiting of challenges to two (incorrect) per set, as originally in the 2007 Australian Open, to reduce the number of more frivolous and tactical challenges, which appear to have been rising in incidence more recently as players have become more used to – and more able to exploit – the system.