Category: Challengers

Identifying Underrated Players With Minor League Elo

I’ve just revised my published Elo ratings (men, women) to better reflect the performance of players who mostly compete at the (men’s) ATP Challenger and (women’s) ITF levels. Previously, my Elo ratings used only tour-level main-draw matches. For top players, it makes very little difference–not only do Novak Djokovic and Simona Halep play no matches at the lower levels, they rarely encounter opponents who spend much time there. But for the second tier of players, the effect can be substantial.

The Elo system rates players according to the quality of their opponents. Beat a good player with a high rating, and your own rating will jump by a healthy margin. Beat a weakling, and your rating will inch up a tiny bit. Essentially, Elo looks at each result and asks, “Based on this new result, how much do we need to adjust our earlier rating?” When Bianca Andreescu upset Caroline Wozniacki in Auckland last week, the system responded by upping Andreescu’s rating by quite a bit, and by penalizing Wozniacki more than for the typical loss. After a more predictable result, like Djokovic’s defeat of Damir Dzumhur, ratings barely move.

It’s important to understand the basic mechanics of the system, but the main takeaway for most fans is that Elo just works. The algorithm generates more accurate player ratings (and resulting match forecasts) than the official ATP and WTA rankings, among other attempts to rank players. Now, you can see Elo rankings for a much wider range of players.

Of of my main uses of Elo ratings is identifying players whose official rankings haven’t caught up to reality. For instance, a few months ago I noted when Daniil Medvedev moved into the Elo top ten, even though he has yet to crack that threshold on the official list. Most players who reach the top ten on the Elo table eventually do the same in the ATP or WTA rankings. Another two current examples are Aryna Sabalenka and Ashleigh Barty, considered by Elo to be two of the top three women on tour right now, even though neither is in the top ten of the WTA rankings. That may be too aggressive, and the margins at the top of the women’s list are tiny right now, but it is a clear signal that these women’s results bear watching. (We talked about this on the most recent Tennis Abstract podcast.)

Now that we have unified Elo lists that cover more players, let’s dig deeper. For each tour, let’s find the players current outside the official top 100s who are rated the highest by the more sophisticated formula. First, the ATP:

Player                  ATP Rank  Elo Rank  
David Ferrer                 124        36  
Thanasi Kokkinakis           145        62  
Miomir Kecmanovic            126        66  
Jack Sock                    105        77  
Reilly Opelka                102        84  
Ricardas Berankis            107        86  
Marcos Baghdatis             122        87  
Gilles Muller                137        88  
Daniel Evans                 190        89  
Viktor Troicki               201        90  
Horacio Zeballos             182        92  
Jared Donaldson              115        94  
Mikael Ymer                  196        95  
Egor Gerasimov               157       100  
Lloyd Harris                 119       102  
Tommy Paul                   195       104  
Guillermo Garcia Lopez       101       106  
Felix Auger Aliassime        106       108  
Alexei Popyrin               149       109  
Dudi Sela                    240       114

One thing that pops out from the list is the number of veterans. Elo ratings are “stickier” than ATP rankings, since the official system works with only 52 weeks worth of results. Elo ratings make constant adjustments, but quality performances–even when they are more than 52 weeks old–continue to affect current ratings for some time. David Ferrer has had a hard time staying healthy enough to compete at his former level, but according to Elo, he remains fairly dangerous when he is able to take the court.

Fortunately the list isn’t all veterans. Elo suggests that younger players such as Thanasi Kokkinakis, Miomir Kecmanovic, Mikael Ymer, and Tommy Paul are better than their current rankings indicate.

The WTA list is even more laden with veterans, players who are still competing at a high level, if not as frequently as they used to:

Player                WTA Rank  Elo Rank  
Lucie Safarova             105        39  
Coco Vandeweghe            100        40  
Shuai Peng                 129        43  
Svetlana Kuznetsova        106        50  
Sara Errani                114        52  
Varvara Lepchenko          134        80  
Laura Siegemund            110        84  
Kristyna Pliskova          101        96  
Anna Kalinskaya            167        97  
Viktorija Golubic          104        98  
Ivana Jorovic              117        99  
Marie Bouzkova             120       103  
Kateryna Bondarenko        140       104  
Sachia Vickery             123       105  
Veronika Kudermetova       111       107  
Sabine Lisicki             198       109  
Vitalia Diatchenko         131       112  
Yanina Wickmayer           126       113  
Nao Hibino                 115       114  
Danielle Lao               169       115

Part of the reason why so few prospects appear on this list is because of my decision to exclude ITF $25Ks. For example, up-and-coming 18-year-old Kaja Juvan, who knocked out Yanina Wickmayer in Australian Open qualifying today, hasn’t played nearly enough matches at higher levels to appear on my Elo list. But last year, she was 29-7 at ITF $25Ks, and won her last ten matches at that level.

Another issue is that the most promising women tend to climb into the top 100 more quickly. Another 18-year-old, Dayana Yastremska, rocketed up the rankings with a tour-level title in Hong Kong last fall. She sits at No. 59 on the WTA table, but after 13 top-100 wins in 2018, Elo is even more optimistic, placing her at No. 27, just ahead of Maria Sharapova and Venus Williams.

I’ll continue to update these expanded Elo ratings weekly and use them to generate forecasts for every tour-level and Challenger event. Enjoy!

Translating ATP Statistics Across Main Tour and Challenger Levels

Italian translation at settesei.it

What is the gap between the top-level ATP Tour and the lower-level ATP Challenger Tour? Some players pile up trophies in the minor leagues yet have a hard time converting that success to match wins on the big tour, while others struggle with the week-to-week grind of the challengers but excel when given opportunities on the larger stage.

Let’s take a look at a method that measures the difference between the skill level on the two tours. Once we can translate stats between levels, we can identify those players who are much better or worse than expected when they have the chance to compete against the best.

The algorithm I’ll use is almost identical to the one baseball analysts have used for decades to determine league equivalencies. For instance, we might find that a batting average of .300 in Triple-A (the highest minor league) is equivalent to .280 in the majors, meaning that, if a player is batting .300 in Triple-A, we’ll expect him to bat .280 in the majors. In tennis terms, it may be that a 10% ace rate in challengers is equivalent to a 8% ace rate on the main tour. Not every player will exhibit that precise drop in performance–some may even appear to get a little better–but on average, a league equivalency tells us what to expect when a player changes levels.

Here is the algorithm for league equivalencies, as applied to men’s tennis:

  1. Pick a stat to focus on. I’ll use Total Points Won (TPW) here.
  2. Neutralize that stat as much as possible. In baseball, that means controlling for the difference in parks; in tennis, it means controlling for competition. For the following, I’ve adjusted for each player’s quality of competition using a method I described about a year ago. Most players’ numbers are about the same after the adjustment, but a particularly easy or tough schedule means a bigger shift. For instance, Denis Shapovalov posted a TPW of 49.8% on the big tour last season, but because he played such high-quality competition, the adjustment bumps him up to 52.1%, 18th among tour regulars.
  3. Identify players who competed at both levels, and find their adjusted stats at each level. Shapovalov played 18 tour-level matches and 30 challenger-level matches last year, with adjusted TPW numbers of 52.1% and 54.4%, respectively.
  4. Calculate the ratio for each player. For Shapovalov last year, it was 1.044 (54.4 / 52.1).
  5. Finally, take a weighted average of every player’s ratio. The weight is determined by the minimum number of matches played at either level, so for Shapovalov, it’s 18. Using the minimum means that a player like Gleb Sakharov (1 ATP match, 37 challenger matches) can be included in the calculation, but has very little effect on the end result.

Here are the results for the last six full seasons. Each ratio is the relationship between challenger-level TPW and tour-level TPW:

Year  Ratio  
2017  1.086  
2016  1.086  
2015  1.098  
2014  1.103  
2013  1.100  
2012  1.100

The average of these yearly equivalency factors is roughly the difference between a 52.5% TPW at challengers and a 48.0% TPW on the main tour. The shift from 2012-15 to 2016-17 may reflect the injuries that have sidelined the elites. With fewer elite players on court, the gap between the two tours narrows.

Now that we know the difference between the levels, we can find the players who defy the usual patterns. Of the 100 players with the most “paired” matches–that is, with the most matches at both levels in the same years–here are the 20 with the lowest ratios. Low ratios mean less difference in performance between the two levels, so these guys are either overperforming at tour level or underperforming at challengers:

Player              ATP M  CH M  Min M  Ratio  
Matthew Ebden          62   140     39  0.982  
Jared Donaldson        68    78     37  1.030  
Jack Sock              81    45     38  1.039  
James Duckworth        53   156     53  1.042  
Andrey Rublev          56    79     42  1.047  
Vasek Pospisil         96    76     60  1.047  
Thiemo De Bakker       48    87     44  1.048  
Samuel Groth           84   133     58  1.049  
Michael Berrer         59   107     56  1.050  
Ruben Bemelmans        41   178     41  1.052  
Dustin Brown          120   173    111  1.055  
Benoit Paire          295    53     53  1.059  
Peter Gojowczyk        46   132     44  1.059  
Michael Russell        58    78     58  1.061  
Marius Copil           58   180     58  1.063  
Taylor Harry Fritz     59    44     41  1.065  
Jordan Thompson        38    88     38  1.066  
Illya Marchenko        56   116     37  1.066  
Tatsuma Ito            65   179     65  1.066  
Ryan Harrison         124    84     59  1.068

The middle columns show the total number of ATP matches, challenger matches, and “paired” matches between 2012 and 2017 (“Min M”) for each player. (The last number gives an indication of just how much data was available for the single-player calculation.) Aside from a few big-serving North Americans near the top of this list, I don’t see a lot of obvious commonalities. There are some youngsters, some veterans, more big servers than not, but nothing obvious.

(Shapovalov doesn’t have enough paired matches to qualify, but his overall ratio is 1.035, good for third on this list.)

Here is the opposite list, the quintile of 20 players who have overperformed at challengers or underperformed on tour:

Player               ATP M  CH M  Min M  Ratio  
Florian Mayer          152    45     45  1.180  
Mikhail Youzhny         91    38     38  1.169  
Aljaz Bedene           144   121     80  1.160  
Filippo Volandri        62   101     62  1.158  
Robin Haase            194    71     71  1.157  
Tobias Kamke           102   144     73  1.155  
Adrian Mannarino       234   115     86  1.155  
Filip Krajinovic        36   167     36  1.148  
Albert Ramos           111    67     62  1.144  
Paul Henri Mathieu     147    96     82  1.141  
Kenny De Schepper       77   196     77  1.140  
Facundo Bagnis          45   197     45  1.136  
Pablo Cuevas           127    52     43  1.136  
Ivan Dodig              76    48     41  1.135  
Santiago Giraldo       146    70     56  1.135  
Paolo Lorenzi          204   191    124  1.135  
Thomaz Bellucci        162    44     44  1.134  
Albert Montanes        113   109     70  1.130  
Rogerio Dutra Silva     57   210     57  1.130  
Lukas Lacko            122   181    108  1.129

There are more clay-courters here than on the first list, and the very top of the ranking includes veterans who have mastered the challenger level, even if they still struggle to maintain a foothold on the main tour. I’ve had to exclude one player who belongs on this list: Gilles Muller broke my algorithm with his 45-9 challenger season in 2014. When I took him out of the 2014 calculations, the overall numbers changed very little, but it means no Muller here. Whatever his exact ratio, I can say that his tour-level performance hasn’t matched that 2014 run at challengers.

The bottoms of the two lists indicate that there isn’t that much variation between players. The middle 60% of players all have ratios between about 1.07 and 1.13, while the yearly averages hover around 1.09 and 1.10. Some players under consideration here have fewer than 50 “paired” matches over the six seasons, so a difference of a couple hundredths is far too little to draw any conclusions.

This algorithm, beyond suggesting what to expect from players when they move up from challengers to the main tour, could apply the same reasoning to other pairs of levels, such as ITF Futures and challengers, or women’s ITFs and the WTA tour. It could even compare narrower levels, such as ITF $10,000 events with ITF $15,000s, or ATP 250s with ATP 500s. The method is a staple of analytics in other sports, and it has a place in tennis, as well.

Benoit Paire and Overqualified Challenger Contenders

Italian translation at settesei.it

With three ATP tour-level events on the slate this week, Benoit Paire considered his options and elected to play none of them. Instead, the world #23 is the top seed at the Brest Challenger, making him the highest ranked player to enter a challenger this year–by a wide margin.

Top-50 players may only enter challengers if they are given a wild card, and top-ten players may not enter them at all. Still, since 1990, a top-50 player has played a challenger just over 500 times, at a rate of about 20 per year. (Some of these players didn’t need a wild card, as entry is determined by ranking several weeks before the tournament, during which time rankings rise and fall.)

Many of the high-ranked wild cards fall into one of two categories: Players who lose early in Slams, Indian Wells, or Miami; and clay-court specialists seeking more matches on dirt. Paire’s decision this week–like the Frenchman himself–doesn’t follow one of these common patterns.

Anyway, here are the top-ranked players to contest challengers since 1990, along with their results. A result of “W” means that the player won the title, while any other result indicates the round in which the player lost.

Year  Event           Player               Rank  Result  
2003  Braunschweig    Rainer Schuettler    8     R16     
1991  Johannesburg    Petr Korda           9     SF      
1994  Barcelona       Alberto Berasategui  10    W       
1994  Graz            Alberto Berasategui  11    R16     
2008  Sunrise         Fernando Gonzalez    12    QF      
2004  Luxembourg      Joachim Johansson    12    W       
2011  Prostejov       Mikhail Youzhny      13    QF      
2008  Prostejov       Tomas Berdych        13    QF      
2003  Prague          Sjeng Schalken       13    W       
2005  Zagreb          Ivan Ljubicic        14    W       
2004  Bratislava      Dominik Hrbaty       14    F       
2004  Prostejov       Jiri Novak           14    QF      
2003  Prostejov       Jiri Novak           14    R32     
2007  Dnepropetrovsk  Guillermo Canas      15    SF      
2002  Prostejov       Jiri Novak           15    F       
1998  Segovia         Alberto Berasategui  15    QF      
1997  Braunschweig    Felix Mantilla       15    F       
1997  Zagreb          Alberto Berasategui  15    W

(Schuettler and Korda were outside the top ten a couple of weeks before their respective challengers.)

A look at this list suggests that Alberto Berasategui entered challengers as a top-fifty player more than anyone else. He’s close–with 12 such entries, he’s tied for second with Jordi Arrese. The player who dropped down a level the most times is Dominik Hrbaty, who played 17 challengers while ranked in the top 50. (The active leaders are Jarkko Nieminen with ten and Andreas Seppi with nine.)

Despite all those attempts, Hrbaty wasn’t particularly successful as a high-ranked challenger player. He won only 2 of those 17 events, reaching only one other final. Top-50 players aren’t guaranteed to win these titles, of course, but in general, they have outperformed Hrbaty, winning 18% of possible titles. Here are top-50 players’ results broken down by round:

Result       Frequency  
Title            18.1%  
Loss in F         9.3%  
Loss in SF       11.3%  
Loss in QF       17.1%  
Loss in R16      22.0%  
Loss in R32      22.2%

Paire is a better player than this sample’s average ranking of 37. Combined with a favorable surface, he gets a much more optimistic forecast from my algorithm, with a slightly better than one-in-three chance of winning the title. With a futures title, an ATP trophy, and a pair of challenger triumphs already in the books this year, it seems fitting that Benoit would add another oddity to his wide-ranging season.

Continue reading Benoit Paire and Overqualified Challenger Contenders

Westerhof, Van Der Duim, and a Strong Whiff of Match Fixing

This afternoon at the ATP Meerbusch Challenger in Germany, all eyes were definitely not on a first-round match between Dutchmen Boy Westerhof and Antal Van Der Duim. Both are ranked outside the top 250, neither has ever cracked the top 200, and both are in their late twenties.

It appears that the two players assumed no one would be watching. Before the match, the markets on Betfair were very suspicious:

For those of you not accustomed to parsing betting markets, here’s a summary of what the market thought was going to happen:

  • Van Der Duim’s chances of winning the match were between 75% and 80%.
  • Van Der Duim’s odds of winning the first set were roughly 35%.
  • There was a better than 50/50 chance that Van Der Duim would win the match in three sets. The odds of any other specific outcome (e.g. Westerhof wins in three) were minuscule in comparison.

The match odds in themselves might have raised a few eyebrows, but could be written off as owing to Westerhof’s recent run of poor play, or perhaps some information gathered on site about a nagging injury. When combined with the other markets, however, it’s clear that something very fishy was going on.

The match went precisely according to script. After Westerhof took the first set, 6-4, the market got more and more confident about Van Der Duim winning the second set:

Van Der Duim remained the favorite even after going down an early break in the second set. Shortly thereafter, with no cameras watching, Westerhof seems to have decided not to waste any more time:

https://twitter.com/baselinebetting/status/498823405282807809

In the end, Van Der Duim beat Westerhof, 4-6 6-3 6-3. No one following the betting markets was at all surprised.

Nor should we be shocked that this sort of thing happens. With the middling prize money on offer at Challenger events–Westerhof will get about $500, and if Van Der Duim loses in the next round, he’ll be awarded about $800–there’s more money to be made by losing matches than winning them.

While we don’t know how often matches are fixed, something was very wrong about this one. Because the markets so blatantly telegraphed the fix, it poses an important question to the sport’s governing bodies. If they don’t take this opportunity to act, it will send a very clear message to Challenger-level players that match-fixing is acceptable practice.

(Thanks to the three Twitter users quoted above, who brought this match to my attention.)

Nick Kyrgios and the First Fifty Matches

Italian translation at settesei.it

When Nick Kyrgios lost the Wimbledon quarterfinal to Milos Raonic yesterday, he was playing his 50th career match at the Challenger level or above. Round numbers invite big-picture analysis, so let’s see how Kyrgios stacks up to the competition at this early milestone.

When Monday’s rankings are released, Nick will debut in the top 100, all way up to #66. Only Rafael Nadal (61), Gael Monfils (65), and Lleyton Hewitt (65) have been ranked higher at the time of their 51th Challenger-or-higher match.  Roger Federer was #93, Novak Djokovic was #128, and Jo Wilfried Tsonga was #314. Of the current top 100, only ten players reached a double-digit ranking by their 51st match.

The wealth of ranking points available at Grand Slams have played a big part in Kyrgios’s rise, but they don’t tell the whole story. He has won 36 of his first 50 matches, equal to the best of today’s top 100. Nadal went 36-14, and next on the list is Djokovic and Santiago Giraldo (who played almost all Challengers) at 34-16. Most of Nick’s wins before this week came at Challengers, and he has won four titles at the level.

No other active player won four Challenger titles in his first 50 matches. Eight others, including Djokovic, Tsonga, Stanislas Wawrinka, and David Ferrer, won three. All of them needed more events at the level to win three titles than Kyrgios did to win four.

Nick’s short Challenger career is another indicator of a bright future. He has only played nine Challenger events, and with his ranking in the 60s, he may never have to play one again. As I’ve previously written, the best players tend to race through this level: Federer, Nadal, and Djokovic all played between eight and twelve Challengers. It’s a rare prospect that makes the jump in fewer than 20 events, and when I researched that post two years ago, more than half of the top 100 had played at least 50 Challengers.

One category in which the Australian doesn’t particularly stand out is age. When he plays his 51st match, he’ll a couple of months past his 19th birthday. Roughly one-quarter of the current top 100 reached that match total at an earlier age. Nadal, Richard Gasquet, and Juan Martin del Potro did so before their 18th birthday, while Djokovic, Hewitt, and Bernard Tomic needed only a few more weeks beyond that.

Without knowing how Kyrgios would’ve performed on tour a year or two earlier, it’s tough to draw any conclusions. His 36-14 record at 19 certainly isn’t as impressive as Rafa’s equivalent record at 17.

Cracking the top 100 at 17 or 18 is a much better predictor of future greatness than doing so at 19, but as the tour ages, 19 may be the new 16. Grigor Dimitrov didn’t enter the top 100 until he was three months short of his 20th birthday, while Dominic Thiem and Jiri Vesely were still outside the top 100 on their 20th birthdays. Among his immediate cohort, Kyrgios stands alone: No other teenager is ranked within the top 240.

As predictive measures go, Nick’s Wimbledon performance–built on his poise under pressure–is the best sign of them all. Only seven active players have reached a Grand Slam quarterfinal as a teenager, and four of them–Fed, Rafa, Novak, and Lleyton–went on to reach #1. (The other three are Delpo, Tomic, and Ernests Gulbis.)

For a player with only fifty matches under his belt, that’s excellent company.

Challenger Tour Finals Forecast

I wrote an extensive preview of this week’s Challenger Tour Finals for The Changeover, so you should check that out first.  (Also worth a read is the preview at Foot Soldiers of Tennis.)

Because so much less separates players at this level (compared to those at last year’s World Tour Finals), my forecast stops just short of throwing its hands up in dismay.  Coming into the event, Italian clay specialist Filippo Volandri was the favorite, with a 15.5% chance of winning the event.  He lost today to Alejandro Gonzalez, making it much less likely that he’ll progress out of the round-robin stage.

Today’s other winners were top seed Teymuraz Gabashvili, Oleksandr Nedovyesov, and Jesse Huta Galung.  My numbers now consider Huta Galung the favorite, with a better than 20% chance of winning the title.  The situation in Grupo Verde will become much more clear after tomorrow’s night match between Gabashvili and Nedovyesov.

Here is the pre-tournament forecast:

Player       3-0  2-1  1-2  0-3     SF      F      W  
Gabashvili   12%  38%  37%  13%  49.8%  24.3%  12.0%  
Volandri     15%  40%  35%  10%  55.3%  29.3%  15.5%  
Nedovyesov   14%  39%  36%  11%  53.0%  26.9%  13.7%  
Huta Galung  14%  39%  36%  11%  53.8%  28.2%  14.6%  
Gonzalez     10%  35%  40%  15%  45.0%  21.8%  10.4%  
Ungur        10%  35%  40%  15%  45.0%  20.9%   9.8%  
Martin       11%  36%  39%  14%  46.0%  22.4%  10.7%  
Clezar       13%  38%  37%  11%  52.2%  26.3%  13.3%

And here is the forecast updated with the results of today’s four matches:

Player       3-0  2-1  1-2  0-3     SF      F      W  
Gabashvili   24%  50%  26%   0%  71.5%  35.0%  17.1%  
Volandri      0%  27%  50%  23%  30.2%  16.2%   8.6%  
Nedovyesov   28%  50%  22%   0%  75.7%  38.3%  19.5%  
Huta Galung  27%  50%  23%   0%  74.7%  39.0%  20.5%  
Gonzalez     23%  50%  27%   0%  70.1%  33.7%  15.8%  
Ungur         0%  22%  50%  29%  23.1%  10.8%   5.1%  
Martin        0%  23%  50%  27%  25.1%  12.2%   5.9%  
Clezar        0%  27%  50%  23%  29.6%  14.9%   7.4%

(My algorithm doesn’t implement the details of the number-of-sets-won tiebreaker, so Guilherme Clezar, the only loser today to win a set, probably has a slightly better chance of advancing than these numbers give him credit for.)

—

Challenger charting: The most interesting match of the day–if not the cleanest–was the last one, between Nedovyesov and Clezar.  I charted it, so you can check out detailed serve, return, and shot-by-shot stats for that contest.

And if you’re really into this stuff–Challengers and/or charting–here are my stat reports from yesterday’s first-round matches in Champaign between Ram and Giron and Sandgren and Peliwo.

Yen Hsun Lu’s Challenger Choices

Yen Hsun Lu has played in a lot of tournaments with fields that look like this month’s Leon and Guadalajara Challengers.  Ranked in the bottom half of the top 100, he is often the only top-100 player in the draw.  In fact, he has been the top seed in every Challenger he’s played for more than a year.

Top seeded or not, Lu seems to really like Challengers.  When other players at his level are contesting ATP 250s or Masters-level qualifying draws, the Taiwanese #1 is demonstrating his dominance of the minor leagues.  And it’s working: In large part thanks to titles in places such as Shanghai, Ningbo, Seoul, and Singapore, he has kept his ranking in the top 100 for about three years.

Lu’s combination of consistency near the top and Challenger preference is unusual but not unique.  He is one of 14 players who, since 2007, have played at least 20 Challenger events while ranked inside the top 100.  He is, however, the most extreme member of the group. This week’s Guadalajara event will be his 40th Challenger as a member of the top 100.  Dudi Sela, also in Guadalajara but currently outside the top 100, has played 31 while part of that more elite club.

Almost every week of the season, there is some tour-level event, and usually, anyone in the top 100 would make the cut for qualifying, if not necessarily the main draw.  But for Lu, the ATP option isn’t always so inviting.  He hates clay, with only two career wins on the surface, one of which was twelve years ago in a Davis Cup Group 2 tie against Pakistan.  (No, not against Qureshi. He lost to Qureshi.)  Despite five entries and a valiant effort in a fifth-set, 11-9 defeat against Jeremy Chardy last year, he has never won a match at Roland Garros.

His Challenger preferences are even more extreme: Out of 137 career events at this level, only two have come on clay.  He is the Alessio Di Mauro of hard courts.

While Sela has a longer track record (and a bit more success) on dirt, his current preferences are very similar.  Given the choice between a hard-court Challenger and anything on clay, and he’ll take the Challenger.  While there aren’t as many tour-level events on clay as Rafael Nadal might like, there are enough to keep Lu and Sela on the lower circuit for several months of the year.

Most of the other players who rack up extensive Challenger records while ranked in the top 100 have the opposite preference.  Filippo Volandri and Ruben Ramirez Hidalgo are the most extreme.  While ranked that high, each has only played three ATP qualifying events, despite entering 29 and 27 Challenger events, respectively, since 2007.  (RRH’s career figures are higher; I’m using the time span since 2007 because my qualifying database only goes back that far.)

Here’s the list of all players who have contested 20 or more Challengers while ranked in the top 100 since 2007, along with the number of ATP qualifying draws they entered while in the top 100 and the rate at which they chose Challengers out of these two options.

Player                 CHs  Qs  CH+Qs  CH/CH+Q  
Yen Hsun Lu             38  10     48      79%  
Dudi Sela               30   6     36      83%  
Filippo Volandri        29   3     32      91%  
Carlos Berlocq          29   5     34      85%  
Michael Russell         28  25     53      53%  
Ruben Ramirez Hidalgo   27   3     30      90%  
Frederico Gil           26  12     38      68%  
Daniel Gimeno Traver    26  21     47      55%  
Nicolas Mahut           22   7     29      76%  
Oscar Hernandez         22   8     30      73%  
Pere Riba               22  11     33      67%  
Tobias Kamke            22  18     40      55%  
Diego Junqueira         21   2     23      91%  
Olivier Rochus          21  11     32      66%

National Showdowns in Challenger Finals

If Dudi Sela and Amir Weintraub both win their semifinal matches at the Leon Challenger today–against Donald Young and Jimmy Wang, respectively–it would the first time that two Israelis face off in a Challenger final, at least since the beginning of 1991, when my challenger database begins.

In over 2800 Challengers in that time span, 407 of them have ended with finals contested between countrymen.  As you might guess, all-USA finals have been the most common, at 84, partly due to the former dominance of Americans in the sport and also owing to the large number of Challengers held on US soil.  Next in line are Argentina (59) and Spain (52), two countries with the key combination of many events and a large pool of second-tier pros.

Perhaps more interesting are the countries at the bottom of list.  Nations like Slovenia*, Taiwan, and Slovakia have more in common with Israel–few events in-country, with just a handful of players contesting Challengers.  Those are the three most recent countries to join the list.  Given the contemporary Challenger field, even more surprising are inclusions such as Norway, Denmark, Mexico, and Morocco, all of which enjoyed all-national Challenger finals in the 90s.

*Slovenia is increasingly becoming a force to be reckoned with.  Led by the underrated Grega Zemlja, it is one of only 12 countries with three players in the ATP top 100.

Given that 29 countries have experienced such a final, we might expect some nations that aren’t on the list.  A few that come to mind are Switzerland (usually better represented than the current two players ranked between 20 and 300), Ukraine (currently six players between #98 and #300), and Portugal (surely Rui Machado and Frederico Gil will meet in a final eventually).

Here’s the full list, including the most recent final for each country:

Country  CH Fs  Date      Event            Winner              Runner-up                
USA      84     20130204  Dallas CH        Rhyne Williams      Robby Ginepri            
ARG      59     20120730  Manta CH         Guido Pella         Maximiliano Estevez      
ESP      52     20121112  Marbella CH      Albert Montanes     Daniel Munoz De La Nava  
GER      39     20130121  Heilbronn CH     Michael Berrer      Jan Lennard Struff       
FRA      36     20121001  Mons CH          Kenny De Schepper   Michael Llodra           
ITA      31     20110718  Orbetello CH     Filippo Volandri    Matteo Viola             
CZE      24     20120312  Sarajevo CH      Jan Hernych         Jan Mertl                
BRA      20     20120910  Cali CH          Joao Souza          Thiago Alves             
AUS      17     20130225  Sydney1 CH       Nick Kyrgios        Matt Reid                
NED      5      20100906  Alphen CH        Jesse Huta Galung   Thomas Schoorel          
BEL      4      20120924  Orleans CH       David Goffin        Ruben Bemelmans          
ROU      4      20120806  Sibiu CH         Adrian Ungur        Victor Hanescu           
AUT      4      20070716  Rimini CH        Oliver Marach       Daniel Koellerer         
COL      3      20120709  Bogota CH        Alejandro Falla     Santiago Giraldo         
JPN      3      20120423  Kaohsiung CH     Go Soeda            Tatsuma Ito              
RSA      3      20110411  Johannesburg CH  Izak Van Der Merwe  Rik De Voest             
SWE      3      19931101  Aachen CH        Jonas Bjorkman      Jan Apell                
RUS      2      20100823  Astana CH        Igor Kunitsyn       Konstantin Kravchuk      
GBR      2      20050704  Nottingham CH    Alex Bogdanovic     Mark Hilton              
CAN      2      19991129  Urbana CH        Frederic Niemeyer   Sebastien Lareau         
IND      2      19990412  New Delhi CH     Leander Paes        Mahesh Bhupathi          
SLO      1      20120716  An-Ning CH       Grega Zemlja        Aljaz Bedene             
TPE      1      20111017  Seoul CH         Yen Hsun Lu         Jimmy Wang               
SVK      1      20100809  Samarkand CH     Andrej Martin       Marek Semjan             
NOR      1      19980601  Furth CH         Christian Ruud      Jan Frode Andersen       
ECU      1      19960715  Quito CH         Pablo Campana       Luis Adrian Morejon      
DEN      1      19960226  Hamburg CH       Kenneth Carlsen     Frederik Fetterlein      
MAR      1      19950814  Geneva CH        Younes El Aynaoui   Karim Alami              
MEX      1      19920427  Acapulco CH      Leonardo Lavalle    Luis Herrera

TennisAbstract.com update: If you like ATP stats, you’ll love the new leaders page.  It allows you to compare the ATP top 50 across nearly 60 different metrics, and filter matches in all the same ways you can on player pages.  Find out who hits the most aces on  clay, who plays the most tiebreaks in Masters events, who has faced the toughest opponents, or just spend the rest of your afternoon tinkering with the thousands of possible permutations.  It’s very much a work in progress, so (a) let me know if you have suggestions or come across a bug; and (b) don’t be shocked if I occasionally break it while trying to improve it.

Also, I’ve created a “current tournaments” page that aggregates all matches (completed and upcoming) at this week’s events.  It’s a great way to get a quick overview of what’s happening this week, and with next week’s qualifying draws released, you can also use the filters to zero in on, say, all Americans who are still alive in some ATP, WTA, or Challenger event.

Finally, don’t miss the Player Schedules page, which aggregates ATP and Challenger entry lists to show you who is playing where for the next six weeks.

The Historically Strong Dallas Challenger

All eyes are on Indian Wells this week, with seven of the top eight-ranked men in the world in the quarterfinals.  (Oh, and one epic streak coming to an end.)  Look a little deeper, though, and you’ll find another ATP event in progress, this one under the guise of a Challenger tournament.

By just about every metric imaginable, this week’s Dallas Challenger has one of the strongest Challenger fields ever assembled.  Many ATP 250s–and a few 500s–are barely at the same level.

Because of Dallas’s timing in between the opening rounds of Indian Wells and the beginning of the Miami Masters, special rules apply to tournament entries.  Higher-ranked players are able to make last-minute decisions to compete, hence the presence of the two top seeds, Marcos Baghdatis and Thomaz Bellucci.  Many other tour-level pros choose to make the stop in Dallas to get a couple of matches under their belt to compensate for a disappointing showing in the California desert.

Measuring field quality is tricky, but here we’re not working with subtle differences.  Here are some simple metrics we could use to the compare main draw strength of the 2500 or so Challenger events since 1991:

  • Average ATP Rank. In Dallas this year, it’s 103, the best ever in a Challenger event.  Second best is 109–that was the same event last year.  Only eight Challengers have ever had an average rank below 130, and the average is a whopping 290.
  • Median ATP Rank. Similar deal, without the risk of a few top players skewing the results.  Dallas’s median is 90; last year it was 90.5–best and second-best ever.  Only two others come in under 100, and the average is 239.
  • 8th seed ATP Rank. I like this metric as it indicates the presumed quality of the quarterfinals–every guy in the last 8 is either this good or has to beat someone this good.  Dallas’s 8-seed this year is #62 Lukas Rosol, the highest-ranked 8-seed ever in a challenger event.  Second place, once again, is the same event last year, where #69 Lukas Lacko was seeded eighth.  Only 18 events have ever had an 8-seed in the top 80, and the historical average is 180.
  • Average seed ATP Rank. Another angle: here Dallas is ousted, coming in 3rd of the 2500 events, at 48.  The 1991 Johannesburg Challenger (46.5) and 1994 Andorra Challenger (47.5) just barely beat it out.  Only 17 events have had an average seed rank better than 60, and the average is 145.
  • Number of top 50 players. Dallas is only the 3rd Challenger event to ever have five top 50 players, after 1991 Jo’burg and 2004 Dnepropetrovsk.  Only 66 Challengers have ever had multiple top-50 competititors, and fewer than 1 in 10 Challengers have a single one.  The average Challenger top seed is ranked #97.
  • Number of top 75/100/125 players.  12 players in the main draw this week are ranked in the top 75, 18 in the top 100, and 25 in the top 125.  All are either new records or tied with the old record.  The average challenger event has 0.13 top-50s, 0.57 top-75s, 1.71 top 100’s, and 3.81 top 125’s.

The one way in which this week’s tournament in Dallas doesn’t rank amongst the best is by a more sophisticated approach, the one that I use in my Challenger strength report on TennisAbstract.com.  By simulating the tournament draw several thousand times, we can estimate the likelihood of a certain level of player winning the event.  For instance, had the 50th-best player in the world entered the Burnie or West Lakes Challenger this year, he would have had about a 25% chance of winning.   But against the more competitive field in Quimper, that number drops to 12%–about the same as the 50th-best player’s chance in the unusually weak Los Angeles ATP event last year.

This week, Jurgen Melzer–ranked in the mid-40s on hard courts by my rating system–had a 9.3% chance of winning the title according to my pre-tourney simulations.  (Go to the tournament forecast page and click ‘R32’ under the ‘Forecast’ header.)  That puts Dallas comfortably among the top 10 toughest Challenger draws in the last year–and better than LA–but nowhere near the top.

It’s one thing to have a deep draw, but another thing entirely to have a tournament that is particularly hard to win.   For the latter, an event needs one or two very highly-ranked players, like Marin Cilic at last year’s Dallas Challenger, or Fernando Verdasco in Prostejov last year.  In theory, if not in practice, someone ranked in the top 20 should waltz to a title, offering an insurmountable obstacle to your typical Challenger-level player.

Dallas may not be the most difficult Challenger event to win, but by any measure of field quality and depth,  it’s one of the very strongest in ATP history.  The fans in Dallas are very fortunate this week.

Nick Kyrgios and the Youngest Challenger Titlists

Last week at the Sydney Challenger, 17-year-old Nick Kyrgios won the title while only dropping a single set.  The young man has been on quite the run, first winning the Australian Open boy’s singles title, reaching the semifinals at his first challenger, then winning in Sydney.

Claiming a title at this level–even against a relatively weak challenger field like that in Sydney–is an impressive feat for any teenager, let alone a 17-year-0ld playing only his second challenger.  And while much has been made of the increasing age of the top ATP contenders, winning a challenger at 17 has never been a common feat.

In fact, this is only the 27th time it has happened, and Kyrgios is only the 16th man to do it.  The list he joins of previous 16- and 17-year-old winners is littered with some of the game’s contemporary greats.  (On Twitter earlier, I offered slightly different numbers; I mistakenly included Donald Young, who won a challenger on his 18th birthday.)

See below for the full list, or click here for a sortable table.

Date      Tournament         Winner                  Age  
20130225  Sydney CH          Nick Kyrgios           17.8  
20100201  Burnie CH          Bernard Tomic          17.3  
20090223  Melbourne CH       Bernard Tomic          16.4  
20060731  Segovia CH         Juan Martin Del Potro  17.9  
20060403  Aguascalientes CH  Juan Martin Del Potro  17.5  
20051031  Montevideo CH      Juan Martin Del Potro  17.1  
20051031  Aachen CH          Evgeny Korolev         17.7  
20050509  San Remo CH        Novak Djokovic         18.0 [17.98]  
20041101  Aachen CH          Novak Djokovic         17.5  
20040517  Budapest CH        Novak Djokovic         17.0  
20030922  Grenoble CH        Richard Gasquet        17.3  
20030811  Graz CH            Tomas Berdych          17.9  
20030728  Segovia CH         Rafael Nadal           17.2  
20030714  Olbia CH           Nicolas Almagro        17.9  
20030714  Budaors CH         Tomas Berdych          17.8  
20030623  Reggio Emilia CH   Richard Gasquet        17.0  
20030421  Napoli CH          Richard Gasquet        16.9  
20030324  Barletta CH        Rafael Nadal           16.8  
20030310  Sarajevo CH        Richard Gasquet        16.7  
20020701  Montauban CH       Richard Gasquet        16.0  
20020513  Fergana CH         Jimmy Wang             17.3  
20020204  Belgrade CH        Mario Ancic            17.9  
20000515  Samarkand CH       Mikhail Youzhny        17.9  
19981207  Perth CH           Lleyton Hewitt         17.8  
19970908  Espinho CH         Marat Safin            17.6  
19950306  Garmisch CH        Nicolas Kiefer         17.7  
19920803  Ribeirao CH        Gabriel Silberstein    17.8