Can pre-tournament form lead to Grand Slam success?
With the the Australian Open just weeks away, our tennis expert, Dan Weston, examines the thorny question of whether pre-tournament tennis form leads to Grand Slam success.
The quandary for ATP tennis players prior to Grand Slams has been well discussed on social media for years. To better inform betting on tennis, it's worth looking at past data to try and answer an important question: do players look to perform well in the week immediately before the big tournament, risking fatigue in the longer best of five-set format, or do they try and rest up, avoiding fatigue but then chancing whether they go into the tournament under-prepared, particularly if they didn’t get much court time the week before?
A detailed look at the tournaments immediately prior to Grand Slams, in the three years between 2016 and 2018, shows that in general, top ten players aren’t hugely interested in participating. Of the 20 applicable events in this time period, only five were won by big names, with Novak Djokovic, (Eastbourne 2017, before Wimbledon, where he took a late wild-card to obtain match practice - currently available at 2.20), Stan Wawrinka (two titles both in his native Geneva - currently available at 35.0) and Dominic Thiem (two titles, both in the French warm-up events before the French Open - currently available at 28.0) being the players lifting trophies.
In these cases, pre-Slam success didn’t have a big impact either way into these three player’s performances in the subsequent Slam event, although none of these did eventually win the title in their relevant Slam event after winning the week before. However, all reached at least the quarter-finals, and their overall record in Slams after winning the week before reads 26-5 (83.9%), and a blind-back of these three players in these scenarios generated a return of around 3% ROI based on a hypothetical flat stake on each player’s Slam match after winning a tournament in the previous week.
Of course, it is impossible to ascertain potential success of such a methodology with such a small sample size of data, so I also ran the numbers on all players who reached at least the semi-finals in events the week prior to a Grand Slam, in order to generate a more concrete assessment of player success compared to market expectations.
What the data says
Interestingly, some players managed regular success in pre-Slam warm-up events. No doubt, if a player is so minded, these tournaments often represent an opportunity to obtain some ‘cheap’ ranking points, with fields often being weaker than equivalent ranking point events during other stages of the season. Having said this, there is that obvious trade-off with potential fatigue before a possibly arduous schedule in the subsequent fortnight.
Players who achieved regular success in the week before Grand Slams include Roberto Bautista-Agut (three titles and another final - currently available at 105), Daniil Medvedev (two titles and a semi-final - currently available at 88.0), Adrian Mannarino (two runners-up spots, and a semi-final), and Steve Johnson (a title, a runners-up spot, and two semi-finals), and this quartet could be worth keeping in mind when looking at outright options in Auckland and Sydney, prior to the Australian Open - these players evidently take the warm-up events pretty seriously. Bautista-Agut has won Auckland twice in the last three years.
So, how did the players who reached at least the semi-finals in events immediately before a Grand Slam fare in the subsequent major tournament? Of the 80 different occasions, 21 lost their first match in the major (26.3%), although it’s worth noting that the winners of the previous week event to a Slam only did so on three occasions out of 20 (15%), although this relative success has to also be tempered by the generally higher calibre of player who won the tournaments.
Overall, though, from a betting perspective, a blind-back of ‘form’ players who performed well in the week immediately prior to a Grand Slam did not fare particularly well. I applied a £100 hypothetical bet to each player for all their relevant Grand Slam matches, with the following results generated based on market closing prices:
As can be seen from the data above, a return on investment of a little worse than -4% is unimpressive, and it is also worth noting that the runners-up category, which boosted profit figures, was based on several outliers - Dan Evans, who shocked Marin Cilic as a heavy underdog in the 2017 Australian Open after reaching the final of Sydney in the prior week, and Adrian Mannarino, who, on his favoured grass, ousted Feliciano Lopez and Gael Monfils, as a 5.00+ underdog on both occasions. If it wasn’t for those two players, overall results would have been considerably worse than they already are.
What can we ascertain from this data in advance of the Australian Open? Well, firstly, we have identified four players who have treated pre-Slam warm-up events pretty seriously in recent years, and these could represent viable outright options for Auckland and Sydney in a week’s time.
In addition, we can see that players have slightly underperformed market expectations in Grand Slams having performed well in the week before the major tournament. It is difficult to establish an exact cause for this, with fatigue a viable explanation, but it is also far from inconceivable that the markets have over-reacted a little to this recent ‘form’ and has weighted this more importantly than any potential fatigue.
It will certainly be interesting to see if this phenomenon continues in 2019.