Jürgen Melzer and Singles Players Who Care About Doubles

This is a guest post by Peter Wetz.

Italian translation at settesei.it

Three weeks ago, Jürgen Melzer played his last singles tournament on home turf at the Erste Bank Open in Vienna. His low singles ranking, caused by injury setbacks and a mediocre comeback campaign, required him to enter into the tournament as a wild card. Melzer drew Milos Raonic in the first round; bookmakers and fans alike predicted that this would be Melzer’s last singles match.

However, things went differently. In front of a packed arena (at least by tournament-Monday standards) Melzer squeezed out a two set win to face Kevin Anderson in the round of 16. That match never happened, though, after a suddenly occurring gastritis forced him to withdraw. As weird as it sounds, this means that Melzer did not lose the last match of his singles career, a feat only a few players can put on their CV.

Another unique thing about Melzer is that he is one of the last players to reach an elite level in singles as well as in doubles. To underline this characteristic let’s start by looking at singles (ChS) and doubles (ChD) career high rankings of  recently-retired1 top ten singles players. The following table shows each player’s peak singles and doubles rankings, sorted by the date at which each player recorded their best singles ranking:

Player			ChS	ChS Date  ChD	ChD Date
Paradorn Srichaphan	9	2003-05	  79	2003-09
Juan Carlos Ferrero	1	2003-09	  198	2003-02
Andy Roddick		1	2003-11	  50	2010-01
Rainer Schuettler	5	2004-04	  40	2005-07
Guillermo Coria		3	2004-05	  183	2004-03
Nicolas Massu		9	2004-09	  31	2005-07
Joachim Johansson	9	2005-02	  108	2005-09
Gaston Gaudio		5	2005-04	  78	2004-06
Guillermo Canas		8	2005-06	  47	2002-07
Mariano Puerta		9	2005-08	  68	1999-08
David Nalbandian	3	2006-03	  105	2009-10
Ivan Ljubicic		3	2006-05	  70	2005-05
Mario Ancic		7	2006-07	  47	2004-06
Radek Stepanek		8	2006-07	  4	2012-11
Nikolay Davydenko	3	2006-11	  31	2005-06
James Blake		4	2006-11	  31	2003-03
Fernando Gonzalez	5	2007-01	  25	2005-07
Robin Soderling		4	2010-11	  109	2009-05
Jürgen Melzer           8       2011-04   6     2010-10
Nicolas Almagro		9	2011-05	  48	2011-03
Mardy Fish		7	2011-08	  14	2009-07
Janko Tipsarevic	8	2012-04	  46	2011-04
Juan Monaco		10	2012-07	  41	2009-01

The data shows that top ten singles players rarely climb up to the very top in doubles. Of course, there can be several reasons for this: scheduling (playing a full singles schedule can be exhausting) or skill (being a good singles player doesn’t necessarily mean that you are also a good doubles player), among others. The fact that the best doubles career high ranking by the Big Four is Roger Federer’s rank of 24 reached in 2003 further underlines that top singles players have better things to do than practicing their volleying skills.

So, as the table above already suggests, Melzer is one of the last of the breed of players that–ranking-wise–made it until the very top in both singles and doubles. The following table shows players who reached a top-ten career high in both rankings, sorted by when they achieved their high in doubles back until 1990.

Player		    ChS	ChS Date   ChD	ChD Date
Petr Korda	    2	1998-02	   10	1990-06
Michael Stich	    2	1993-11	   9	1991-03
Marc Rosset	    9	1995-09	   8	1992-11
Yevgeny Kafelnikov  1	1999-05	   4	1998-03
Patrick Rafter	    1	1999-07	   6	1999-02
Wayne Ferreira	    6	1995-05	   9	2001-03
Jiri Novak	    5	2002-10	   6	2001-07
Jonas Björkman	    4	1997-11	   1	2001-07
Arnaud Clement	    10	2001-04	   8	2008-01
Jürgen Melzer	    8	2011-04	   6	2010-10
Radek Stepanek	    8	2006-07	   4	2012-11
Fernando Verdasco*  7	2009-04	   8	2013-11
Jack Sock*	    8	2017-11	   2	2018-09

* Active singles player

Since 1990 there have only been 13 players who reached a doubles and singles career high inside the top ten. The last number one with a top ten doubles ranking was Patrick Rafter. Currently there are only two active singles players part of this group. As has already been mentioned on this blog several times, Jack Sock’s doubles prowess is an exception no matter how you look at it. And the time between Fernando Verdasco’s singles high and doubles high shows that he reached them at two completely different stages of his career, which brings us to the final measure: Which players held a top ten spot in both rankings at the same time? The following table shows players, weeks spent in the singles top ten (weeksS), weeks spent in the doubles top ten (weeksD) and weeks spent in both singles and doubles top ten at the same time (weeksS+D) sorted by the date the doubles career high was reached.

Player		weeksS	weeksD	weeksS+D Chd Date
John Mcenroe	208	96	74	 1983-01
Pat Cash	89	14	5	 1984-08
Anders Jarryd	82	379	78	 1985-08
Mats Wilander	227	72	72	 1985-10
Stefan Edberg	452	122	117	 1986-06
Guy Forget	79	119	5	 1986-08
Yannick Noah	157	87	84	 1986-08
Andres Gomez	143	62	31	 1986-09
Boris Becker	530	21	21	 1986-09
Joakim Nystrom	72	57	33	 1986-11
Miloslav Mecir	109	19	19	 1988-03
Emilio Sanchez	57	138	44	 1989-04
Jakob Hlasek	37	132	10	 1989-11
Yevgeny Kafeln.	388	157	148	 1998-03
Patrick Rafter	156	33	26	 1999-02
Jonas Björkman	43	462	29	 2001-07
Jürgen Melzer	14	50	14	 2010-09

With Melzer’s retirement, there is no active player who held a top ten ranking in singles and doubles at the same week. In other words, he is the last player who held simultaneous top ten rankings in singles and doubles. With Jonas Björkman this makes him one of only two players in this group for the past 18 years! Even in the nineties there were only two players–Rafter and Yevgeny Kafelnikov–reaching this feat, whereas in the eighties there were many others.

Even if this stream of trivia does not tell us much analytically, we can see that players peaking with and without partners on their side of the court are becoming a rare species. The times when they have done so simultaneously are long gone.

Footnotes

1. We look at retired players, because their career high rankings are not subject to change anymore.

Peter Wetz is a computer scientist interested in racket sports and data analytics based in Vienna, Austria.

Forecasting the 2018 Laver Cup

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Italian translation at settesei.it

It’s that time of year again: group selfies in suits, dodgy Davis Cup excuses, and a reminder that it takes more than six continents just to equal Europe. That’s right, it’s Laver Cup.

Last year, I worked out a forecast of the event, walking through a variety of ways in which captains Bjorn Borg and John McEnroe could use their rosters and ultimately predicting a 16-8 win for Team Europe. As it happened, both captains intelligently deployed their stars, and the result was 15-9. This year, the competitors are a little different and the home court has moved from Prague to Chicago, but the format remains the same.

Let’s start with a look at the rosters. I’ve included two additional players for reference: Juan Martin del Potro, scheduled to play for Team World, but withdrew; and Pierre Hugues Herbert, the doubles specialist Borg hasn’t realized he needs. Each player is shown alongside his surface-weighted singles Elo rating and surface-weighted doubles “D-Lo” rating:

EUROPE                       Singles Elo  Doubles D-Lo  
Novak Djokovic                      2137          1667  
Roger Federer*                      2097          1700  
Alexander Zverev                    1971          1690  
David Goffin                        1960          1582  
Grigor Dimitrov                     1928          1719  
Kyle Edmund                         1780          1542  
                                                        
WORLD                        Singles Elo  Doubles D-Lo  
Kevin Anderson                      1914          1692  
Nick Kyrgios                        1910          1668  
John Isner                          1887          1800  
Diego Sebastian Schwartzman         1814          1540  
Frances Tiafoe                      1772          1544  
Jack Sock                           1724          1925  
                                                        
ALSO                                                    
Juan Martin Del Potro               2062          1678  
Pierre Hugues Herbert               1691          1890

* Federer has played very little tour-level doubles for a long time. Last year I estimated his D-Lo at 1650; he played rather well last year, so I’ll bump him up to 1700 this time around.

Especially with Delpo on the sidelines, Europe looks to dominate the singles. The doubles leans in World’s favor, largely because Jack Sock is so good, especially in comparison with guys who have focused on singles.

Format review

Let’s do a quick refresher on the format. Laver Cup takes place over three days, each of which has three singles matches and one doubles match. Each player must play singles at least once, and no doubles pairing can repeat itself. Day 1 matches are worth one point each, day 2 matches are worth 2 points each, and day 3 matches are worth 3 points each. If there’s a 12-12 tie at the end of day 3, a single doubles set–in which a previously-used team may compete–will decide it all.

Given that format, the best way for the captains to use their rosters is to stick their three worst singles players on day 1 duty, then use their best three on both day 2 and day 3. For doubles, they should use their best doubles player every day, with the best partner on day 3, next best on day 2, and third best on day 1. As I’ve mentioned, Borg and McEnroe came close to this last year, although Borg didn’t use Rafael Nadal (his best doubles player) in day 3 doubles, and he generally overused Tomas Berdych. Both decisions are understandable, as Nadal may not have been physically able to play every possible match, and Berdych was in front of a Czech crowd.

Now that we know the captains will act in a reasonably savvy way, we can forecast the second edition with a little more confidence than the inaugural one.

The forecast

Nadal’s absence this year will hurt the Europe squad on both singles and doubles. Combined with a small step backward for Federer’s singles game, this year’s Laver Cup figures to be closer than last year. Recall that my forecast a year ago called for a 16-8 Europe victory, and the result was 15-9.

Assuming optimal usage, the 2018 forecast gives Europe a 67.6% chance of winning, with a most likely final score of 14-10. There’s a nearly one-in-ten shot that we’ll see a 12-12 tie, in which the superior doubles capabilities of Team World give them the edge, with a 70.7% probability of winning the tie-breaking set.

Were del Potro not so fragile, this could get even more interesting. Swap out Frances Tiafoe for the Tower of Tandil, and Europe’s chances fall to 56.8%, with a most likely final score of 13-11.

Nothing McEnroe could have done, short of going to medical school a few decades ago, could have put the Argentine on his team this week. But Borg has less of an excuse for failing to maximize the potential of his team. Unlike World, with its world-beating doubles specialist, Europe has a stunning singles roster that rarely takes to the doubles court. As we’ve seen, one doubles player can take the court three times, plus the potential 12-12 tie-breaking set. The specialist would need to play singles only once, on the low-leverage first day.

The obvious choice is Pierre Hugues Herbert, a top-five doubles player with the ability to play respectable singles as well. The Frenchman would be considerably more valuable than Kyle Edmund, who is a better singles player, but not good enough to be of much help to an already loaded side. (I made a similar point last year and illustrated it with Herbert’s partner, Nicolas Mahut. Since then, Herbert has taken the lead over his Mahut in both singles and doubles Elo ratings.)

When we sub in Herbert for Edmund, the simulation spits out the best result yet for Europe. Against the actual World team (that is, no Delpo), the hypothetical Europe squad would have a 74.6% chance of winning, with the likely final score between 14-10 and 15-9. Herbert and a mediocre partner would still be the underdogs in a tie-breaking final set against Sock and John Isner, but the presence of a legitimate doubles threat would narrow the odds to about 58/42.

We won’t get to see either Delpo or Herbert in Chicago this year, but we can expect a slightly more competitive Laver Cup than last year. Add in home court advantage, and the result is even less of a foregone conclusion. It’s no match for last week’s Davis Cup World Group play-offs, but I suspect it’ll make for more compelling viewing this weekend than the final rounds in Metz and St. Petersburg.

Jack Sock, Doubles King Once Again

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Italian translation at settesei.it

A couple of years ago, I wrote an article introducing D-Lo, an Elo-like rating system for doubles, which crowned Jack Sock as the best doubles player on the men’s tour. Sock grabbed the top spot in October 2016 and hung on for about nine months, largely by not playing very much. A couple of first-round losses in Washington and Montreal last summer sent him tumbling, landing at 8th after the US Open and as low as 14th going into this year’s Australian Open.

Despite his preference for singles, Sock has rocketed back into the lead, first pairing with John Isner for the Indian Wells title, and then partnering Mike Bryan (replacing injured brother Bob) to win both Wimbledon and the US Open. With the exception of one week immediately after Indian Wells, Sock sits at the head of the D-Lo table for the first time in more than a year. Here are the current top ten, along with their ratings:

Rank  Player                 D-Lo  
1     Jack Sock              1949  
2     Bob Bryan              1930  
3     Mike Bryan             1917  
4     Pierre Hugues Herbert  1906  
5     Nicolas Mahut          1893  
6     Jamie Murray           1886  
7     Bruno Soares           1883  
8     Oliver Marach          1867  
9     Robert Farah           1863  
10    Nikola Mektic          1863

Yes, that’s the injured Bob Bryan in the second spot. More on that in a moment.

A quick refresher on the D-Lo system: It mostly works like a standard Elo algorithm, in that players gain points for winning matches and lose points for losing them, based on the quality of the opponent and the amount of prior information already baked into their ratings. A big upset earns more points than a victory over an equal, and for players with fewer prior matches, the effect of each match is greater. Thus, Sock got a few more points than Mike did for winning the 12 matches at the last two slams, because we knew relatively less about him before those tournaments.

D-Lo assumes that the quality of each team is equal to the average of the two players. If a team wins, each member of the partnership gains points, with one tweak: If the two players have different ratings, their ratings slightly move toward the average of the two. This is because it’s impossible to know how much each player contributes to a win. The system is designed so that, after a year or so of playing together, the two mens’ ratings will meet in the middle. It’s an imperfect system, but it does a reasonably good job of forecasting results, which means it usually provides a solid representation of each player’s skill level.

Back to the matter at hand: Doubles ratings have been particularly volatile this year, with five different men (Sock, Bob, Pierre Hugues Herbert, Mate Pavic, and Henri Kontinen) holding the #1 spot, and two more (Nicolas Mahut and John Peers) peaking at #2. This parity means that no player has a particularly high rating. Two years ago, Sock’s mark of 1949 would have been good for only fourth (behind himself, Herbert, and Mahut), and several players (the Bryans, Herbert, and Daniel Nestor among them) have peaked with ratings above 2000.

Take a look at how much the rank order has fluctuated since the beginning of 2018:

2018 D-Lo leaders

For clarity’s sake, I’ve left off Oliver Marach (whose rating tracks closely with that of his partner, Pavic, and whose season hasn’t lived up to its early promise) and Peers (ditto, with Kontinen). Herbert has reached the highest level of anyone this season, but a rough second half so far has left him behind the American trio of Jack, Bob, and Mike.

Back to the curious case of Bob Bryan. The Bryan brothers’ title at the Madrid Masters this year gave the twins their highest D-Lo ratings in nearly two years. “Standard” Elo doesn’t penalize players for absence, so Bob’s mark has remained at 1930 ever since. (I’ve added an injury/absence penalty in my singles Elo ratings, but haven’t done so for D-Lo. I suspect there is less of an effect, but still a measureable one, in doubles.) Mike’s rating has slipped because of some bad results apart from the pair of majors, and only Sock has caught up.

If Bob is healthy enough to play this fall, the twins are expected to pair up for the World Tour Finals, once again leaving the best doubles player in the world out of the field. In that case, Sock, down to 157th in the ATP singles race, could end up spending that week playing the new ATP Challenger event in Houston. Without their young compatriot in the way, the Bryans will be back in familiar territory, headed to London as the favorites for another year-end title.

Men’s Doubles Season Starts and the Case of Oliver Marach and Mate Pavic

This is a guest post by Peter Wetz.

In recent years, the steady decline of the holders of 116 doubles titles–Bob and Mike Bryan–has resulted in more variety at the very top of the game. The 16-time Grand Slam champions won their last major at the US Open 2014. Since then, eight different teams have won their first title at the highest level of the sport.

Even though none of these debut winners emerged out of nowhere, the doubles team consisting of Oliver Marach and Mate Pavic, which formed in the middle of last season, has enjoyed an exceptional run at this year’s start of the season. This prompted me to take a closer look at the performance of doubles teams per season.

The following table shows each team’s won-loss record through the French Open for each season since 2000 . It’s sorted by number of  wins up to that point, and the last column displays the won-loss record for the complete season. Only teams that have won more than 30 matches until the French Open are listed.

Year	Team		W-L (%) Start	W-L (%) Full
2013	Bryan/Bryan	40-4  (91%)	71-11 (87%)
2002	Knowles/Nestor	38-7  (84%)	66-14 (82%)
2007	Bryan/Bryan	37-5  (88%)	73-10 (88%)
2008	Bryan/Bryan	37-9  (80%)	63-17 (79%)
2009	Bryan/Bryan	37-9  (80%)	68-18 (79%)
2014	Bryan/Bryan	36-6  (86%)	64-12 (84%)
2018	Marach/Pavic	36-7  (84%)	tbd
2010	Nestor/Zimonjic	35-7  (83%)	57-19 (75%)
2012	Mirnyi/Nestor	34-9  (79%)	43-18 (70%)
2003	Knowles/Nestor	34-9  (79%)	57-16 (78%)
2006	Bryan/Bryan	33-9  (79%)	65-15 (81%)
2004	Bryan/Bryan	32-8  (80%)	57-17 (77%)
2010	Bryan/Bryan	31-7  (82%)	67-13 (84%)
2011	Bryan/Bryan	31-7  (82%)	59-16 (79%)
2009	Nestor/Zimonjic	31-8  (79%)	57-17 (77%)
2014	Nestor/Zimonjic	31-8  (79%)	42-18 (70%)
2003	Bryan/Bryan	31-12 (72%)	54-20 (73%)

As we can see, Marach/Pavic come in seventh with a very healthy 36-7 won-loss record this year. Their first loss came in the Rotterdam final, their fourth tournament after collecting titles in Doha, Auckland, and at the Australian Open–a streak of 17 consecutive match wins. If we ignore the all-time greats, there hasn’t been a better start to a men’s doubles season in the past 16 years.

The fact that the Bryan twins show up ten out of seventeen times in the table underlines just how dominant they were. And even though they did not win a Grand Slam in the last three years, they still had the best season starts in 2015 and 2016 (just barely missing the table, because they did not reach 30 match wins).

The last column gives a clue of what to expect from Marach and Pavic for the rest of the year. Most of the time, the teams at the very top only slightly decline. Notably, in 2007 the Bryan brothers maintained a win percentage of 88%, which led to the best doubles season in the dataset, measured by won-loss record.

After losing their seventh match this season at the 2018 French Open final to Herbert/Mahut and therefore missing the chance to win the first two majors of the season–a feat achieved in the open era only by the Bryans in 2013–it will be interesting to see if they will be able to sustain their level over a full season.

Peter Wetz is a computer scientist interested in racket sports and data analytics based in Vienna, Austria.

Men’s Doubles On the Dirt

Angelique Kerber wasn’t the only top seed to crash out early at this year’s French Open. In the men’s doubles draw, the top section opened up when Henri Kontinen and John Peers, the world’s top-ranked team, lost to the Spanish pair of David Marrero and Tommy Robredo. It’s plausible to attribute the upset to the clay, as Kontinen-Peers have tallied a pedestrian five wins against four losses on the dirt this season and one could guess that the Spaniards are at their strongest on clay.

Fortunately we don’t have to guess. Using a doubles variant of sElo–surface-specific Elo, which I began writing about a few days ago in the context of women’s singles–we can make rough estimates of how Kontinen/Peers would fare against Marrero/Robredo on each surface. The top seeds are solid on all surfaces–less than a year ago, they won a clay title in Hamburg–but stronger on hard courts. sElo ranks them 4th and 8th on hard, but 10th and 13th on clay among tour regulars.  Marrero is the surface-specialist of the bunch, ranking 37th on clay and 78th on hard. Robredo throws a wrench into the exercise, as he has played very little doubles recently, only eight events since the beginning of 2016.

Using these numbers–including those derived from Robredo’s limited sample–we find that sElo would have given Kontinen/Peers a 73.6% chance of winning yesterday, compared to a 78.3% advantage on a hard court. Even if we adjust Robredo’s clay-court sElo to something closer to his all-surface rating, the top seeds still look like 69% favorites.

A more striking example comes from yesterday’s other big upset, in which Julio Peralta and Horacio Zeballos took out Feliciano Lopez and Marc Lopez. On any surface, the Lopezes are the superior team, but Peralta and Zeballos have a much larger surface differential:

Player    Hard sElo  Clay sElo  
M Lopez        1720       1804  
F Lopez        1713       1772  
Zeballos       1651       1756  
Peralta        1517       1770

On a hard court, sElo gives the Lopezes a 68.1% chance of winning this matchup. But on clay, the gap narrows all the way to 53.6%. It’s still a bit of an upset for the South Americans, but not one that should come as much of a surprise.

Mismatches

I’ve speculated in the past that surface preferences aren’t as pronounced in doubles as they are in singles. Regardless of surface, points are shorter, and many teams position one player at the net even on the dirt. While some hard-courters are probably uncomfortable on clay (and vice versa), I wouldn’t expect the effects to be as substantial as they are in singles.

The numbers tell a different story. Here are the top ten, ranked by hard court sElo:

Rank  Player          Hard sElo  
1     Jack Sock            1947  
2     Nicolas Mahut        1893  
3     Marcelo Melo         1883  
4     Henri Kontinen       1879  
5     P-H Herbert          1862  
6     Bob Bryan            1851  
7     Mike Bryan           1846  
8     John Peers           1842  
9     Bruno Soares         1829  
10    Jamie Murray         1828

By clay court sElo:

Rank  Player                Clay sElo  
1     Mike Bryan                 1950  
2     Bob Bryan                  1950  
3     P-H Herbert                1894  
4     Nicolas Mahut              1889  
5     Jack Sock                  1887  
6     Robert Farah               1850  
7     Juan Sebastian Cabal       1849  
8     Pablo Cuevas               1824  
9     Rohan Bopanna              1812  
10    John Peers                 1810

Jamie Murray and Bruno Soares, who appear in the hard court top ten, sit outside the top 25 in clay court sElo. Robert Farah and Juan Sebastian Cabal are 41st and 42nd in hard court sElo, despite ranking in the clay court top seven. Pablo Cuevas, another clay court top-tenner, is 87th on the hard court list.

To go beyond these anecdotes–noteworthy as they are–we need to compare the level of surface preference in men’s doubles to other tours. To do that, I calculated the correlation coefficent between hard court and clay court sElo for the top 50 players (ranked by overall Elo) in men’s doubles, men’s singles, and women’s singles. (I don’t yet have an adequate database to generate ratings for women’s doubles.)

In other words, we’re testing how much a player’s results on one surface predict his or her results on the other major surface. The higher the correlation coefficient, the more likely it is that a player will have similar results on hard and clay. Here’s how the tours compare:

Tour             Correl  
Men's Singles     0.708  
Women's Singles   0.417  
Men's Doubles     0.323

In contrast to my hypothesis above, surface preferences in men’s doubles appear to be much stronger than in either men’s or women’s singles. (And there’s a huge difference between men’s and women’s singles, but that’s a subject for another day.)

Randomness

I suspect that the low correlation of surface-specific Elos in men’s doubles is partly due to the more random nature of doubles results. Because the event is more serve-dominated, there are more close sets ending in tiebreaks, and because of the no-ad, super-tiebreak format used outside of Slams, tight matches are decided by a smaller number of points. Thus, every doubles player’s results–and their various Elo ratings–reflect the influence of chance more than the singles results are.

Another consideration–one that I haven’t yet made sense of–is that surface-specific ratings don’t improve doubles forecasts they way that they do men’s and women’s singles predictions. As I wrote on Sunday, sElo represents a big improvement over surface-neutral Elo for women’s forecasts, and in an upcoming post, I’ll be able to make some similar observations for the men’s game. Using Brier score, a measure of the calibration of predictions, we can see the effect of using surface-specific Elo ratings in 2016 tour-level matches:

Tour             Elo Brier  sElo Brier  
Men's Singles        0.202       0.169  
Women's Singles      0.220       0.179  
Men's Doubles        0.171       0.181

The lower the Brier score, the more accurate the forecasts. This isn’t a fluke of 2016: The differences in men’s doubles Brier scores are around 0.01 for each of the last 15 seasons. By this measure, Elo does a very good job predicting the outcome of men’s doubles matches, but the surface-specific sElo represents a small step back. It could be that the smaller sample–using only one surface’s worth of results–is more damaging to forecasts in doubles than it is in singles.

Doubles analytics is particularly uncharted territory, and there’s plenty of work remaining for researchers even in this narrow subtopic. There’s lots of work to do for the world’s top doubles players as well, now that we can point to a noticeably weaker surface for so many of them.

Albert Ramos’s Record-Setting Doubles Futility

Last week, we learned that Albert Ramos is not very good at doubles. In Barcelona, he lost his first-round doubles match, running his losing streak to 21 straight and his career tour-level record to an astonishing 14-79.

Ramos hasn’t won a doubles match since Marrakech last year, so he has fallen off the doubles ranking list entirely. Elo isn’t so kind: Of the 268 players with at least one tour-level doubles match since 2014, Ramos ranks dead last, with an Elo rating of 1260, 130 points behind the second worst, Paul-Henri Mathieu, and 240 points below the default rating of 1500 given to a player when he first arrives on tour. If two players with Ramos’s rating were to play an elite team like Kontinen/Peers, Elo would give the Ramos team little more than a 2% chance of winning.

It turns out that the Barcelona loss was a notable one, setting the mark for the longest tour-level doubles losing streak since 2000. Here is the list:

PLAYER               LOSSES     YEARS  
Albert Ramos             21   2016-17*  
Florent Serra            20   2008-10  
Lars Burgsmuller         18   2001-03  
Ryan Sweeting            17   2010-12  
Mikhail Kukushkin        17   2014-16  
Gael Monfils             16   2012-15  
Jack Waite               16   2001-02  
Mikhail Youzhny          16   2002-03  
Luke Jensen              15   2000-02  
Ratiwatana brothers      15   2008-09  
Taylor Dent              15   2001-04

* active streak

My database isn’t as complete before 2000, so I can’t confidently say whether there were longer streaks earlier in ATP history.

Among active players, Ramos’s run of futility stands far above the pack. There are 14 players with active streaks of 8 or more tour-level losses, though as you’ll see, I’m defining “active” quite broadly:

PLAYER                STREAK  START  
Albert Ramos              21   2016  
Lukas Lacko               13   2012  
James Ward                11   2010  
Marinko Matosevic         11   2014  
Jimmy Wang                11   2006  
Zhe Li                    11   2010  
Omar Awadhy               10   2002  
Jose Rubin Statham        10   2006  
Mikhail Youzhny           10   2015  
Paul Henri Mathieu         9   2016  
Juan Monaco                9   2015  
Lucas Pouille              8   2016  
Andre Begemann             8   2016  
Daniel Gimeno Traver       8   2015

Many of the players on this list are attempting comebacks from injury or trying to rebuild their rankings to enter more ATP events, so few of them are likely to threaten Ramos’s mark. If he continues on tour, Mathieu may have the best chance: He has racked up five different losing streaks of 8 or more matches, including a 12-loss stretch between 2002 and 2005.

One of the things that makes Ramos’s streak so remarkable is that he has continued to enter doubles draws so frequently, playing both singles and doubles in 20 of his 31 events. Some of his peers have had poor doubles seasons, but few of them have kept trying so assiduously. Here are the 15 players with the worst doubles winning percentages in the last 52 weeks, minimum 10 matches:

PLAYER                   MATCHES  WINS  WIN PERC  
Albert Ramos                  20     0      0.0%  
Jiri Vesely                   10     1     10.0%  
Alexander Bury                13     2     15.4%  
Taylor Fritz                  11     2     18.2%  
Gilles Simon                  11     2     18.2%  
Benoit Paire                  16     3     18.8%  
Inigo Cervantes Huegun        10     2     20.0%  
Lucas Pouille                 15     3     20.0%  
Hans Podlipnik Castillo       13     3     23.1%  
Paolo Lorenzi                 33     8     24.2%  
Marcos Baghdatis              12     3     25.0%  
Adrian Mannarino              15     4     26.7%  
Andreas Seppi                 15     4     26.7%  
Joao Sousa                    30     8     26.7%  
Neal Skupski                  17     5     29.4%

Paolo Lorenzi might be a bit better than his position on this list makes him look: Over the last year, he has partnered Ramos four times, more than any other player.

Then again, Lorenzi has struggled with plenty of doubles partners. Here are the least successful doubles players since 2000, minimum 50 matches:

PLAYER              MATCHES  WINS  WIN PERC  
Albert Ramos             93    14     15.1%  
Robby Ginepri            97    21     21.6%  
Gilles Simon            151    33     21.9%  
Gael Monfils             92    21     22.8%  
Adrian Mannarino         58    14     24.1%  
Benoit Paire             93    23     24.7%  
Paul Henri Mathieu      105    26     24.8%  
Jack Waite               68    17     25.0%  
Florent Serra            72    18     25.0%  
Santiago Giraldo         99    27     27.3%  
Aleksandar Kitinov       88    24     27.3%  
Marinko Matosevic        61    17     27.9%  
Bernard Tomic            63    18     28.6%  
Younes El Aynaoui        56    16     28.6%  
Paolo Lorenzi           104    30     28.8%

Ramos, once again, is in a league of his own. Beyond him and Robby Ginepri, the list is dominated by a surprising number of Frenchmen, including Florent Serra, who outranks several of his countrymen, but appeared earlier with the 20-match losing streak that Ramos finally overtook.

Ironically, since Ramos’s losing streak has coincided with career-best success on the singles circuit, he will find it easier than ever to enter doubles draws. With the press that comes with the streak, however, potential partners may finally think twice before signing up with the worst tour-level doubles player of their generation.

Podcast Episode 2: Doubles, Wild Cards, and Megastars

In the second episode of the Tennis Abstract Podcast, Carl Bialik and I give some much-deserved top billing to doubles, especially new ATP No. 1 Henri Kontinen and Elo doubles favorite Jack Sock.

We also cover the role of megastars in tennis, and the benefits and challenges they offer to the sport’s promoters. As we discuss, big names may be key to expanding the appeal of doubles, and they are the one major argument for the continuing existence of wild cards–on whichever side of the Maria Sharapova debate you find yourself.

Listen here, subscribe on iTunes, or use our feed to get updates on your favorite podcast software.

 

New at Tennis Abstract: ATP Doubles!

At last, I’ve added ATP doubles results to player pages at Tennis Abstract. Doubles has long been relegated to second-class status by tennis analytics, largely because the data just isn’t there. Now, much more is readily available.

Tennis Abstract now has career doubles results (including Challengers, Futures, and Satellites) for thousands of ATP players, and they’ll be updated throughout each day’s play, just like singles results. Match times and traditional match stats are included for most 2016 ATP and Challenger tournaments, and I hope that will continue to be the case in 2017 and beyond.

Let me give you a brief tour of what you’ll find, using doubles legend Jack Sock as a starting point:

The big red “1” shows where to click to switch over to doubles results. For full-time doubles specialists, you won’t have to click–the site will automatically show you doubles results.

The “2” indicates three new doubles-specific filters: by partner, by opponent, and by opposing team. For instance, you can see Sock’s results with Vasek Pospisil, his eight matches against Daniel Nestor, or his twelve meetings with the Bryan Brothers. You may always combine multiple filters, so for example, you can look at Sock’s record against the Bryans only when partnering Pospisil.

There are three more new filters, marked by the big “3” toward the bottom. The “vs Hands” filter allows you to select matches against righty-righty, righty-lefty, or lefty-lefty teams. “Partner Hand” and “Partner Rank” make it possible to limit matches to those in which the partner had certain characteristics.

Finally, the “4” shows you where to access more detailed stats. Doubles results take a lot more room to display than singles results, so on the default view, the only “stats” on offer are match time and Dominance Ratio. Click on “Serve,” “Return,” or “Raw” to get the other traditional numbers, such as ace rate, first-serve points won, or break points converted. All of these numbers are totals for each team; individual player stats are almost never available for doubles matches.

I hope you enjoy this new resource. It’s something I’ve wanted for a long time, so I’m excited to be able to use it myself. There are still some minor gaps in the record, as well as some kinks in the functionality, so please be patient as I try to work all of that out.

For those of you who’d like to see WTA doubles results, as well: Me too! I can’t promise any particular deadline, but I’ve already done much of the work to build the dataset, so I’m hoping to add them to women’s player pages early this year. Stay tuned!

The Unexpectedly Predictable IPTL

December is here, and with the tennis offseason almost five days old, it’s time to resume the annual ritual of pretending we care about exhibitions. The hit-and-giggle circuit gets underway in earnest tomorrow with the kickoff, in Japan, of the 2016 IPTL slate.

The star-studded IPTL, or International Premier Tennis League, is two years old, and uses a format similar to that of the USA’s World Team Tennis. Each match consists of five separate sets: one each of men’s singles, women’s singles, (men’s) champions’ singles, men’s doubles, and mixed doubles. Games are no-ad, each set is played to six games, and a tiebreak is played at 5-5. At the end of all those sets, if both teams have the same number of games, representatives of each side’s sponsors thumb-wrestle to determine the winner. Or something like that. It doesn’t really matter.

As with any exhibition, players don’t take the competition too seriously. Elites who sit out November tournaments due to injury find themselves able to compete in December, given a sufficient appearance fee. It’s entertaining, but compared to the first eleven months of the year, it isn’t “real” tennis.

That triggers an unusual research question: How predictable are IPTL sets? If players have nothing at stake, are outcomes simply random? Or do all the participants ease off to an equivalent degree, resulting in the usual proportion of sets going the way of the favorite?

Last season, there were 29 IPTL “matches,” meaning that we have a dataset consisting of 29 sets each of men’s singles, women’s singles, and men’s doubles. (For lack of data, I won’t look at mixed doubles, and for lack of interest, forget about champion’s singles.) Except for a handful of singles specialists who played doubles, we have plenty of data on every player. Using Elo ratings, we can generate forecasts for every set based on each competitor’s level at the time.

Elo-based predictions spit out forecasts for standard best-of-three contests, so we’ll need to adjust those a bit. Single-set results are more random, so we would expect a few more upsets. For instance, when Roger Federer faced Ivo Karlovic last December, Elo gave him an 89.9% chance of winning a traditional match, and the relevant IPTL forecast is a more modest 80.3%. With these estimates, we can see how many sets went the way of the favorite and how many upsets we should have expected given the short format.

Let’s start with men’s singles. Karlovic beat Federer, and Nick Kyrgios lost a set to Ivan Dodig, but in general, decisions went the direction we would expect. Of the 29 sets, favorites won 18, or 62.1%. The Elo single-set forecasts imply that the favorites should have won 64.2%, or 18.6 sets. So far, so predictable: If IPTL were a regular-season event, its results wouldn’t be statistically out of place.

The results are similar for women’s singles. The forecasts show the women’s field to be more lopsided, due mostly to the presence of Serena Williams and Maria Sharapova. Elo expected that the favorites would win 20.4, or 70.4% of the 29 sets. In fact, the favorites won 21 of 29.

The men’s doubles results are more complex, but they nonetheless provide further evidence that IPTL results are predictable. Elo implied that most of the men’s doubles matches were close: Only one match (Kei Nishikori and Pierre-Hugues Herbert against Gael Monfils and Rohan Bopanna) had a forecast above 62%, and overall, the system expected only 16.4 victories for the favorites, or 56.4%. In fact, the Elo-favored teams won 19, or 65.5% of the 29 sets, more than the singles favorites did.

The difference of less than three wins in a small sample could easily just be noise, but even so, a couple of explanations spring to mind. First, almost every team had at least one doubles specialist, and those guys are accustomed to the rapid-fire no-ad format. Second, the higher-than-usual number of non-specialists–such as Federer, Nishikori, and Monfils–means that the player ratings may not be as reliable as they are for specialists, or for singles. It might be the case that Nishikori is a better doubles player than Monfils, but because both usually stick to singles, no rating system can capture the difference in abilities very accurately.

Here is a summary of all these results:

Competition      Sets  Fave W  Fave W%  Elo Forecast%  
Men's Singles      29      18    62.1%          64.2%  
Women's Singles    29      21    72.4%          70.4%  
ALL SINGLES        58      39    67.3%          67.3%  
                                                       
Men's Doubles      29      19    65.5%          56.4%  
ALL SETS           87      58    66.7%          63.7%

Taken together, last season’s evidence shows that IPTL contests tend to go the way of the favorites. In fact, when we account for the differences in format, favorites win more often than we’d expect. That’s the surprising bit. The conventional wisdom suggests that the elites became champions thanks to their prowess at high-pressure moments; many dozens of pros could reach the top if they were only stronger mentally. In exhos, the mental game is largely taken out of the picture, yet in this case, the elites are still winning.

No matter how often the favorites win, these matches are still meaningless, and I’m not about to include them in the next round of player ratings. However, it’s a mistake to disregard exhibitions entirely. By offering a contrast to the high-pressure tournaments of the regular season, they may offer us perspectives we can’t get anywhere else.

Forecasting Davis Cup Doubles

One of the most enjoyable aspects of Davis Cup is the spotlight it shines on doubles. At ATP events, doubles matches are typically relegated to poorly-attended side courts. In Davis Cup, doubles gets a day of its own, and crowds turn out in force. Even better, the importance of Davis Cup inspires many players who normally skip doubles to participate.

Because singles specialists are more likely to play doubles, and because most Davis Cup doubles teams are not regular pairings, forecasting these matches is particularly difficult. In the past, I haven’t even tried. But now that we have D-Lo–Elo ratings for doubles–it’s a more manageable task.

To my surprise, D-Lo is even more effective with Davis Cup than it is with regular-season tour-level matches. D-Lo correctly predicts the outcome of about 65% of tour-level doubles matches since 2003. For Davis Cup World Group and World Group Play-Offs in that time frame, D-Lo is right 70% of the time. To put it another way, this is more evidence that Davis Cup is about the chalk.

What’s particularly odd about that result is that D-Lo itself isn’t that confident in its Davis Cup forecasts. For ATP events, D-Lo forecasts are well-calibrated, meaning that if you look at 100 matches where the favorite is given a 60% chance of winning, the favorite will win about 60 times. For the Davis Cup forecasts, D-Lo thinks the favorite should win about 60% of the time, but the higher-rated team ends up winning 70 matches out of 100.

Davis Cup’s best-of-five format is responsible for part of that discrepancy. In a typical ATP doubles match, the no-ad scoring and third-set tiebreak introduce more luck into the mix, making upsets more likely. A matchup that would result in a 60% forecast in the no-ad, super-tiebreak format translates to a 64.5% forecast in the best-of-five format. That accounts for about half the difference: Davis Cup results are less likely to be influenced by luck.

The other half may be due to the importance of the event. For many players, regular-season doubles matches are a distant second priority to singles, so they may not play at a consistent level from one match to the next. In Davis Cup, however, it’s a rare competitor who doesn’t give the doubles rubber 100% of their effort. Thus, we appear to have quite a few matches in which D-Lo picks the winner, but since it uses primarily tour-level results, it doesn’t realize how heavily the winner should have been favored.

Incidentally, home-court advantage doesn’t seem to play a big role in doubles outcomes. The hosting side has won 52.6% of doubles matches, an edge which could have as much to do with hosts’ ability to choose the surface as it is does with screaming crowds and home cooking. This isn’t a factor that affects D-Lo forecasts, as the system’s predictions are as accurate when it picks the away side as when it picks the home side.

Forecasting Argentina-Croatia doubles

Here are the D-Lo ratings for the eight nominated players this weekend. The asterisks indicate those players who are currently slated to contest tomorrow’s doubles rubber:

Player                 Side  D-Lo     
Juan Martin del Potro  ARG   1759     
Leonardo Mayer         ARG   1593  *  
Federico Delbonis      ARG   1540     
Guido Pella            ARG   1454  *  
                                      
Ivan Dodig             CRO   1856  *  
Marin Cilic            CRO   1677     
Ivo Karlovic           CRO   1580     
Franco Skugor          CRO   1569  *

As it stands now, Croatia has a sizable advantage. Based on the D-Lo ratings of the currently scheduled doubles teams, the home side has a 189-point edge, which converts to a 74.8% probability of winning. But remember, that’s the chance of winning a no-ad, super-tiebreak match, with all the luck that entails. In best-of-five, that translates to a whopping 83.7% chance of winning.

Making matters worse for Argentina, it’s likely that Croatia could improve their side. Argentina could increase their odds of winning the doubles rubber by playing Juan Martin del Potro, but given Delpo’s shaky physical health, it’s unlikely he’ll play all three days. Marin Cilic, on the other hand, could very well play as much as possible. A Cilic-Ivan Dodig pairing would have a 243-point advantage over Leonardo Mayer and Guido Pella, which translates to an 89% chance of winning a best-of-five match. Even Mayer’s Davis Cup heroics are unlikely to overcome a challenge of that magnitude.

Given the likelihood that Pella will sit on the bench for every meaningful singles match, it’s easy to wonder if there is a better option. Sure enough, in Horacio Zeballos, Argentina has a quality doubles player sitting at home. The two-time Grand Slam doubles semifinalist has a current D-Lo rating of 1758, almost identical to del Potro’s. Paired with Mayer, Zeballos would bring Argentina’s chances of upsetting a Dodig-Franco Skugor team to 43%. Zeballos-Mayer would also have a 32% chance of defeating Dodig-Cilic.

A full Argentina-Croatia forecast

With the doubles rubber sorted, let’s see who is likely to win the 2016 Davis Cup. Here are the Elo– and D-Lo-based forecasts for each currently-scheduled match, shown from the perspective of Croatia:

Rubber                      Forecast (CRO)  
Cilic v Delbonis                     90.8%  
Karlovic v del Potro                 15.8%  
Dodig/Skugor v Mayer/Pella           83.7%  
Cilic v del Potro                    36.3%  
Karlovic v Delbonis                  75.8%

Elo still believes Delpo is an elite-level player, which is why it makes him the favorite in the pivotal fourth rubber against Cilic. The system is less positive about Federico Delbonis, who it ranks 68th in the world, against his #41 spot on the ATP computer.

These match-by-match forecasts imply a 74.2% probability that Croatia will win the tie. That’s more optimistic than the betting market which, a few hours before play begins, gives Croatia about a 65% edge.

However, most of the tweaks we could make would move the needle further toward a Croatia victory. Delpo’s body may not allow him to play two singles matches at full strength, and the gap in singles skill between him and Mayer is huge. Croatia could improve their doubles chances if Cilic plays. And if there is a home-court or surface advantage, it would probably work against the South Americans.

Even more likely than a Croatian victory is a 1-1 split of the first two matches. If that happens, everything will hang in the balance tomorrow, when the world tunes in to watch a doubles match.