Margin of Error Podcast: Episode 21

A new podcast is out!

Amy and I have plenty to say about the final 16 (or 18, or 19) men and women at Wimbledon. We take you through the first week’s upsets, marathons, and controversies, and look ahead to how the final rounds will play out.

You can find the podcast and subscribe with iTunes here. For other subscription methods, here’s an XML feed. Otherwise, keep an eye out for a new episode early each week, which I’ll post here on the blog.

Click here to listen.

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Margin of Error Podcast: Episode Twenty with Carl Bialik

Our Wimbledon preview podcast is out!

With Wimbledon only hours away, Amy and I are joined by FiveThirtyEight.com’s Carl Bialik as we preview the upcoming Grand Slam.

You can find the podcast and subscribe with iTunes here. For other subscription methods, here’s an XML feed. Otherwise, keep an eye out for a new episode early each week, which I’ll post here on the blog.

Click here to listen.

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Teenagers, Thirty-Somethings, and Americans at Grand Slams

I’ve put together a few reports showing how age distributions and US presence have changed over the years at Grand Slams.  Let’s start with player age.

The average age of players in the Wimbledon men’s singles draw is 27.7 years, which is just short of the all-time record, 27.8, set at Roland Garros last month, and equal to last year’s figure at Wimbledon. There are two teens in the draw (up one from last year), and 34 thirty-somethings, which is tied for third-most since 1982.

This report shows the complete year-by-year breakdown for the last 30 years’ worth of men’s slam draws.

The average age in the Wimbledon women’s draw is also very high by historical standards.  At 25.2 years, it’s tied with this year’s French Open and 2012 Wimbledon for the highest ever.  43-year-old Kimiko Date Krumm moves the needle all by herself; without her, the average would be 25.0, still considerably higher than any other pre-2010 slam.

There are ten teenagers in the draw, which is very low for the WTA, but safely above the all-time low of 7, set at Wimbledon two years ago. The total of 16 players aged 30 or over is good for third-most of all time, behind this year’s and last year’s French Opens.

Here’s the WTA report showing these numbers for each slam in the last 30 years.

(All of the figures above for 2014 Wimbledon could change slightly if more lucky losers are added to the draw.)

I also put together a couple of reports showing the number of Americans in each slam draw, broken down by direct entrants, qualifiers, lucky losers, and wild cards, along with the top seed, the number of seeds (and top 16 seeds), plus the number of Americans in each round:

Enjoy!

 

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Filed under Aging trends, American tennis, Grand Slams, Wimbledon

Margin of Error Podcast: Episode Nineteen

We missed a week, so you’ll never know what we thought about the conclusion of the French Open … but we’re back, and almost as good as usual.

A week into grass season, Amy and I take you through the results in Halle, Birmingham, and London while looking ahead to this week in Eastbourne, s’Hertogenbosch, and Wimbledon qualifying.

You can find the podcast and subscribe with iTunes here. For other subscription methods, here’s an XML feed. Otherwise, keep an eye out for a new episode early each week, which I’ll post here on the blog.

Click here to listen.

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Margin of Error Podcast: Episode Eighteen

A new podcast is out!

It’s the midway point of the French Open, so Amy and I recap the action so far and preview the final eight men and women.

You can find the podcast and subscribe with iTunes here. For other subscription methods, here’s an XML feed. Otherwise, keep an eye out for a new episode early each week, which I’ll post here on the blog.

Click here to listen.

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The Effect of 32 Seeds

In the middle of 2001, the Grand Slams doubled the number of seeds in the draw from 16 to 32, a change “designed to protect star players and satisfy clay and grass specialists.”

The intended beneficiaries of the change were, of course, all seeded players. Those in the top 16 no longer had to worry about facing a fellow top-32 player until the third round. Those ranked from 17-32, who before the change may have faced a top 16 player in the first round, now received the same protection.

The costs of the 32-seed system are borne by two groups: unseeded players, who are now more likely to face a top-ranked player early; and first-week fans, who would like to see more “compelling” early-round matches. While it’s easy to point to shock upsets like Serena Williams’s exit today as a counterpoint, the first two rounds at Slams often feel like warm-up matches for the biggest stars, with fringe players as their hapless foils.

On the other hand, it’s tough to get an intuitive sense of just how much is at stake here. It may not be as much as you think. From 1989 to 2000, men’s seeds were upset 263 times in the first two rounds of slams. Only 51 of those losses were to players in the top 32. In other words, more than 80% of those upsets would have occurred even with a 32-seed format, and presumably, some of the remaining 51 matches would still have resulted in upsets.

From the perspective of the top 16 seeds, there may not be that much difference between opponents ranked in the next 16 and those ranked lower still. To cherry-pick just one example, there are many seeded players Stanislas Wawrinka would have rather faced this week than Guillermo Garcia Lopez.

For top-four women, it hasn’t made a difference at all. In the twelve years before the switch, they reached the third round in 176 of 190 attempts. In the twelve years after the format change, women seeded 1-4 no longer risked facing a top-32 player in the first two rounds, and reached the third round in 178 of 191 attempts.

In fact, for top-16 women’s seeds in general, the 32-seed format has not helped. From 1989-2000, women’s seeds reached the third round 77.6% of the time, the fourth round 63.5% of the time, and the quarterfinals 40.8% of the time. From 2002-13, with lower-ranked early-round opponents, the corresponding numbers were 78.2%, 60.1%, and 37.1%.

It’s likely that some of the differences have to do with the increasing depth of the women’s game, but it’s hardly the case that the 32-seed format has drastically changed the nature of the majors, at least for the players who have been seeded all along. Men’s top-16 seeds have benefited, reaching the third, fourth, and quarterfinal rounds about 10% more often since the switch to 32 seeds, but even here, we’re not seeing radically different second weeks.

The real change, as you might suspect, appears when we consider the balance of power between the new seeds (17-32) and the rest of the field. From 1989-2000, when there were only 16 seeds and those two groups were treated the same way, men’s players ranked 17-32 reached the third round about twice as often (35% to 17%) as their lower-ranked competitors. Women in the 17-32 range held a wider advantage of 39% to 15%.

Now that there are 32 seeds and the 17-32 group is protected, those gaps have substantially grown. From 2002-13, men seeded outside the top 16 have reached the third round 53% of the time, compared to 12% for unseeded players. Seeded women in the 17-32 range have reached the third round 49% of the time, while unseeded women have equaled their male counterparts at 12%.

These differences, big as they are, aren’t going to affect most fans’ enjoyment of the majors. The format change means that Rafael Nadal faces a player ranked 60th in the world in the second round and a player ranked 30th in the third round. He’ll almost always win both matches, so the end result is the same. A surprise run to the quarterfinals isn’t much different if it’s made by world #25 than by #50.

However, the 32-seed format does amplify the gap between tennis’s haves and have-nots. Yes, he Grand Slams have massively increased prize money in the last few years for all main-draw competitors–first-round losers in Paris earn more than $32,000 for their efforts. But players who reach the third round are able to triple that money.

As we’ve seen, the format change has made it much more likely that #32 reaches the third round (and takes home a nearly six-figure purse) at the expense of everyone ranked lower–despite having little effect on the makeup of the field in the fourth round and beyond.  Plus, the ranking points on offer at Slams mean that third-rounders are that much more likely to earn a seed at the next major, starting the next round of the same cycle.

Seeding 32 players instead of 16 doesn’t have much of an effect on the fates of top players, especially on the women’s side. It can, however, lessen interest in the first several days of play, and it certainly supports an arbitrary middle tier of players at the expense of the rest of the field.

If the 32-seed era were to end here, there’s little reason for tennis fans to miss it.

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Erratic Results and the Fate of Jerzy Janowicz

When Jerzy Janowicz defeated Victor Estrella in the first round at Roland Garros on Sunday, it was the Pole’s first win since Februrary, breaking a string of nine consecutive losses. Janowicz’s results have been rather pedestrian ever since his semifinal run at Wimbledon last year, yet the 720 points he earned for that single performance have kept his ranking in the top 25 and given him a seed at the Grand Slams.

As we’ve discussed many times on this site, occasional greatness trumps consistent mediocrity, at least as far as ranking points are concerned. The system rewards players who bunch wins together–Janowicz current holds about 1500 points, barely double what he earned from that single event last year.

In the short term, bunching wins is a good thing, as Janowicz has learned. But from an analytical perspective, how should we view players with recent histories like his? Does the Wimbledon semifinal bode well for the future? Does the mediocre rest of his record outweigh a single excellent result? Does it all come out in the wash?

It’s a question that doesn’t pertain only to Janowicz. While 48% of Jerzy’s points come from Wimbledon, 49% of Andy Murray‘s current ranking point total comes from winning Wimbledon. Another reigning Slam champion, Stanislas Wawrinka, owes 34% of his point total to a single event.  By contrast, for the average player in the top 50, that figure is only 21%. Rafael Nadal and Novak Djokovic are among the most consistent on tour, at 16% and 10%, respectively.

Since 2010, there has only been one top-40 player who earned more than half of his year-end ranking points from a single event: Ivan Ljubicic, whose 1,000 points for winning Indian Wells dominated his 1,965 point total. His top-16 ranking at the end of that year didn’t last. He didn’t defend his Indian Wells points or make up the difference elsewhere, falling out of the top 30 for most of 2011. Of course, he was in his 30s at that point, so we shouldn’t draw any conclusions from this extreme anecdote.

When we crunch the numbers, it emerges that there has been no relationship between “bunched” ranking points and success the following year. I collected several data points for every top-40 players from the 2010, 2011, and 2012 seasons: their year-end ranking, the percentage of ranking points from their top one, two, and three events, and the year-end ranking the following year.  If bunching were a signal of an inflated ranking–that is, if you suspect Janowicz’s abilities don’t jibe with his current ranking–we would see following-year rankings drop for players who fit that profile.

Take Jerzy’s 2012, for example. He earned 46% of his points from his top event (the Paris Masters final), 53% from his top two, and 57% from his top three.  (Corresponding top-40 averages are 21%, 34%, and 44%.)  He ended the year with 1,299 ranking points. At the end of 2013, his ranking no longer reflected his 600 points from Paris. But unlike Ljubicic in 2010, Janowicz boosted his ranking, improving 24% to 1,615 points.

The overall picture is just as cloudy as the juxtaposition of Ljubicic and Janowicz. There is no correlation between the percentage of points represented by a player’s top event (or top two, or top three) and his ranking point change the following year.

For the most extreme players–the ten most “bunched” ranking point totals in this dataset–there’s a small indication that the following season might disappoint. Only three of the ten (including Janowicz in 2012-13) improved their ranking, while three others saw their point total decrease by more than 40%. On average, the following-year decrease of the ten most extreme player-seasons was approximately 20%. But that’s a small, noisy subset, and we should take the overall results as a stronger indication of what to expect from players who fit this profile.

There’s still a case to be made that Jerzy is heading for a fall. He hasn’t racked up many victories so far this year that would offset the upcoming loss of his Wimbledon points. And his Wimbledon success was particularly lucky, as he faced unseeded players in both the fourth round and the quarterfinals. Even if he is particularly effective on grass, it’s unlikely the draw will so heavily favor him again.

But however a player earns his disproportionately large point total, the points themselves are no harbinger of doom. On that score, anyway, Janowicz fans can expect another year in the top 25.

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