2018 US Open: Glicko Preview

Ahead of the 2018 US Open, our Betfair tennis expert & Data Scientist Martin Ingram, gives his Glicko 2018 US Open Tennis Predictions for the Men’s and Women’s tournaments and reveals the two players he believes will be hard to beat.


ABOUT THE AUTHOR: MARTIN INGRAM – DATA SCIENTIST

Martin is passionate about good code and gaining insights from data with a particular interest in sports analytics. He completed a Bachelor Of Arts, Natural Sciences (Physical) at Cambridge before completing his Masters of Science, Computing Science.


The 2018 US Open is about to start, and it promises to be an exciting event. On the men’s side, after the resurgence of Nadal and Federer in the last year, Novak Djokovic has reappeared at the very highest level, winning Wimbledon and Cincinnati. For the women, Halep has had a great year so far, but Serena Williams is in the middle of her comeback and there are plenty of other challengers, too.

In this preview, I use Glicko, a ratings system developed by Harvard Professor Mark Glickman, to predict this year’s U.S. Open.  Glicko is a generalisation of the Elo rating system which considers not just a player’s mean skill, but also the uncertainty about that skill. This allows it to deal more naturally with player absences and skill changes over time.

To take surface differences into account, I blend each player’s overall Glicko rating with a separate rating fit only to hard courts. After optimising for best predictive performance, the optimal weighting is about 75% overall + 25% hard courts for both men and women.


PlayerMean skillUncertainty
(1) Federer R.204573
(2) Nadal R.203966
(3) Djokovic N.196966
(4) del Potro J.190861
(5) Murray A.*190186
(6) Kyrgios N.182466
(7) Raonic M.181566
(8) Cilic M.181258

Surface Glicko has two favourites for the US Open: Federer and Nadal. At 2045 and 2039 points, respectively, they are virtually tied for first spot.

Federer had a great start to this year, winning his 20th Grand Slam title at the Australian Open, but since then has looked more vulnerable than he did at this stage last year. Most recently, Djokovic beat him easily in the Cincinnati final, a tournament which Federer had won seven times in the past. Still, with a rating of 2045, Glicko would still have him as the slight favourite against Djokovic in a rematch (60% win probability).

While there are some doubts about Federer’s form, Nadal has looked strong, most recently winning Toronto. Nadal has had a good season, triumphing at the French Open for an incredible eleventh time and reaching the semi-finals of Wimbledon, losing only to a resurgent Novak Djokovic.

Djokovic comes in at number three, 70 points behind Nadal. His victory at Cincinnati was impressive, but he has also had a number of surprising losses this year, losing to Tsitsipas in Toronto, for example. Still, if his form continues from Cincinnati, he should be a strong contender for the title.

Juan-Martin del Potro is ranked at number 4. He had a very strong start to the year, winning his first Masters 1000 title in Indian Wells, but has had some injury issues since. He recently reached the finals in Los Cabos and lost in the quarter finals of Cincinnati to David Goffin, suggesting that he may not be at his very best.

Andy Murray’s ranking is still high, at 1901, but it is not clear what his real skill is at this point. He has only played seven matches since returning from a hip injury, losing five of them. This is why I have put an asterisk next to his name – although Glicko is faster than Elo at adjusting to injury, it may not have seen enough of Murray to adjust enough.

Kyrgios, Raonic and Cilic round out the top 8. Kyrgios has had mixed results this year and struggled with injury, most recently losing to del Potro in Cincinnati. Raonic has been playing stronger recently after a slow start to the year; he lost only to Djokovic at Cincinnati in three sets. Finally, Cilic should not be counted out: he played well but lost to eventual champions Nadal and Djokovic in Toronto and Cincinnati, both in three tight sets.

Winners and losers compared to last year

The biggest gains were made by Stefanos Tsitsipas, who gained an astonishing +305 Glicko points compared to last year. Hyeon Chung (+127), Juan Martin del Potro (+126), Rafael Nadal (+125) and Borna Coric (+92) have also improved substantially.

On the other hand, Stan Wawrinka (-89), Novak Djokovic (-85), Tomas Berdych (-81), Denis Shapovalov (-66) and Andy Murray (-66) have had a mixed year.

PlayerMeanUncertainty
(1) Halep S.190369
(2) Kvitova P.180368
(3) Svitolina E.179372
(4) Kerber A.179071
(5) Wozniacki C.178276
(6) Williams S.177794
(7) Bertens K.174965
(8) Garcia C.174869

For the women, surface Glicko has one strong favourite: Simona Halep. She has a 100-point lead over the rest of the field, which would make her a 63% favourite in a match against Petra Kvitova, ranked second. Halep has looked strong overall recently, winning Montreal and reaching the finals of Cincinnati, cementing her role as the favourite.

Behind Halep, players are ranked much more closely together, with only 55 points separating Kvitova from Caroline Garcia, ranked eigth. Kvitova has had reasonable results, reaching the semi-finals in Cincinnati and the second round in Montreal (losing to Bertens both times) but most recently retired from New Haven, which puts a question mark around her current fitness.

Elina Svitolina is ranked at number three. Her struggles at Grand Slams are well known: so far, she has failed to get past the quarter finals of any grand slam. Her results in this year’s warmups have been fairly good: she lost in the semi-finals of Montreal, and the quarter finals of Cincinnati (to Bertens, who eventually won the title).

Angelique Kerber trails Svitolina by just three points. She recently won Wimbledon and has had a good year overall, recovering from her terrible 2017 season. However, her results in Montreal and Cincinnati were not good: she lost in the first and second rounds, respectively, suggesting she is currently not playing her best.

Caroline Wozniacki finally won her first Grand Slam at the Australian Open this year but has had mixed results since. At Wimbledon, she was defeated in the second round. Since then she lost in the first round of Montreal (to Sabalenka) and retired against Bertens in the first round of Cincinnati.

Serena Williams is ranked sixth by Glicko. Her comeback after becoming a mother has had ups and downs. She reached the finals of Wimbledon, losing to Kerber, but had tough losses since, losing 6-1 6-0 to Konta in Stanford, and in three sets to Kvitova in Cincinnati. A six-time winner at the US Open, she should still not be counted out.

Kiki Bertens and Caroline Garcia round out the top 8. Bertens recently had a fantastic run in Cincinnati, beating (among others) Wozniacki, Svitolina, Kvitova and Halep to win the title. If she can play at a similar level at the US Open, she could be a strong contender for the title. Garcia, on the other hand, has not been as successful of late, losing in the quarters of Montreal (to Halep), the second round of Cincinnati (to Sabalenka) and the quarters of New Haven (to Puig).

Winners and losers compared to last year

Aryna Sabalenka made the biggest gains over the last year, adding a huge +247 Glicko points to her rating. Amanda Anisimova (+222), Kiki Bertens (+222) and Mihaela Buzarnescu (+217) also improved a great deal.

On the other hand, Svetlana Kuznetsova (-104), Garbine Muguruza (-91), Serena Williams (-66) and Johanna Konta (-65) have not had a good year overall.


Summary

On the men’s side, the favourites are Nadal, Federer and Djokovic, as they have been for so many years. It will be fascinating to see how strongly each of them play at the US Open, with Glicko suggesting that Nadal and Federer may still have a slight edge over Djokovic. Although they do not quite make the top 8 favourites the ATP’s next generation players, such as Alexander Zverev and Stefanos Tsitsipas (who made the biggest gains of all compared to last year) will also be worth keeping an eye on.

For the women, after many Grand Slams with the field ranked very closely together, Simona Halep has been able to separate herself from the other players by a slight margin. It will be interesting to see whether Kiki Bertens can keep up her form from Cincinnati, how strongly Serena Williams will play, and whether Elina Svitolina can finally get past the quarters of a Grand Slam.


Betting Strategy

 BACK – Rafael Nadal in the Men’s tournament

 BACK – Simona Halep in the Women’s tournament


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