Category: Tennis

Wimbledon Men’s and Women’s Semifinal Preview

It’s time for the Final Four – of Wimbledon! – and just like this past March, we’re missing a few notable favorites. Roger Federer, Serena Williams, Venus Williams, and even women’s no. 1 Caroline Wozniacki are out of the tournament.

Our new Wimbledon ratings have shown, however, that these types of early exits were to be expected coming in to this year’s event. Here’s a quick look back at the results from the quarterfinals, and a peek forward to see what might happen in the final two rounds.


The big news in the quarterfinals was Roger Federer’s exit, his second straight in the fifth round after seven consecutive years in the finals.

The way it happened (a comeback from 2 sets down by Jo-Wilfried Tsonga) makes the upset seem shocking, but our Wimbledon predictions actually showed it as the most likely upset going in to the quarterfinals. While anybody who looks as much like Muhammad Ali as Tsonga does always has a puncher’s chance, Federer’s age appears to have brought him back to the pack, making upsets of him far more common.

With Federer gone, there are really just two players left with significant chances: Rafael Nadal and Novak Djokovic. Read more »

Wimbledon Math: More Details On The “Odd Odds” For Victoria Azarenka

In our previous post on the 4th-round women’s Wimbledon upsets, we mentioned that as of June 27, Victoria Azarenka seemed to be undervalued at Betfair. That’s a bit of a simplification. What we really believe is that there seems to be something funny going on with the women’s Wimbledon futures at Betfair, which makes the odds for Azarenka, Kvitova, and Paszek illogical when viewed in context of each other.

My guess is that it’s a result of there simply not being a very big market for “Player X to make the Final” at this point in the tourney, so the market isn’t liquid enough to be fully efficient. At any rate, here’s the situation. Read more »

Wimbledon Upsets: With Serena Williams, Venus Williams, and Wozniacki Out, Who’s In The Driver’s Seat?

The Women’s side of Wimbledon got a big shake-up yesterday as both Williams sisters and Caroline Wozniacki lost. Entering the tournament, according to our new Wimbledon women’s rankings, they were the three top favorites to win it all (!), so the field is suddenly wide open.

At first glance, the three losses are pretty spectacular, especially Venus’s loss to Tsvetana Pironkova. Given their specific 4th-round matchups, according to our ratings the chances of all three players losing were just short of 1%, the kind of odds that make you question the accuracy of the ratings system.

However, going into the tournament, our Wimbledon women’s predictions indicated the chances of making it past round 4 for Serena, Venus, and Caroline were 50.0%, 48.8%, and 48.3% respectively. So individually, all three of these players had about a 50/50 chance of getting bounced from Wimbledon on or before yesterday. In fact, as indicated in the notes on our player pages, a fourth round exit was the second most likely individual result for both Serena Williams and Venus Williams.

It’s the fact that all three got upset in round 4 that was so unlikely.

Still, a couple factors in the 2011 women’s bracket — the lack of front-runners and three-set (as opposed to five-set) match lengths — do make upsets more likely than on the men’s side. Read more »

Introducing the Wimbledon Ratings and Wimbledon Predictions

Wimbledon started earlier this week, and we’ve decided to create a version of the power ratings to help predict the winner. It’s a little late getting up, but we are now unrolling on the site men’s Wimbledon ratings and Wimbledon women’s rankings, along with Wimbledon predictions and Wimbledon women’s predictions as of the start of the tournament. Here’s a quick explanation of both.

Wimbledon Ratings

The Wimbledon rankings are predictive power ratings, and use results from all of the matches since January 1st, 2010. The ratings themselves don’t correspond to margin of victory as they do for other sports, but they allow an easy way to predict an individual’s chance of winning a match.

For the Wimbledon women’s rankings, if a player with rating A plays a player with rating B, their chance of winning the match is A/(A+B). For the men it’s similar, but the formula gives their chance of winning a set, making it easy to adjust for best of 3 or best of 5. Looking at how these ratings would’ve fared, they correctly picked almost 70% of game winners. Read more »