Prospects – Heavy Topspin

Tomas Machac’s Defiant Angles

*Tomas Machac at the 2023 US Open. Credit: Hameltion*

2024 is quickly turning into the year of Tomas Machac. The 23-year-old Czech reached his first grand slam third round in Australia, straight-setting Frances Tiafoe for a first top-20 win. A quarter-final showing in Marseille and a defeat of Stan Wawrinka at Indian Wells earned him a place in the top 60.

Now, in Miami, he has dispatched top-tenner Andrey Rublev and outlasted Andy Murray for a place in the fourth round. The live rankings place him precariously in the top 50; tomorrow’s match against fellow second-week surprise Matteo Arnaldi give him a chance to make it official. While Jiri Lehecka, a year younger and considerably higher in the rankings, is the poster boy for the resurgence of Czech men’s tennis, Machac is right behind him.

The key to the Machac game is a compact, versatile backhand that seems capable of anything. Inside-out backhands are usually little more than a curiosity, a miracle of timing that many players don’t even bother to try. The Czech hits one in ten of his backhands that way. Against Rublev, he cracked five: one for a winner and two more that forced errors. He won all five.

The tactics that surround Machac’s backhand are a joy to watch. Since he doesn’t serve big, every point threatens to become a rally. But the Czech angles for court position like a much bigger hitter. He approached the net 35 times in yesterday’s Murray match alone. Counting the times he was forced to come forward as well, he played 48 points in the forecourt, winning 38 of them. Combined with a court-widening slice serve, the net play makes Machac just as much of a threat on the doubles court. With Zhang Zhizhen, he reached the semi-finals in Australia and won the title in Marseille. He and girlfriend Katerina Siniakova would make a dangerous mixed duo at the Paris Olympics.

The unknowns that could limit Machac’s ceiling are, well, everything else. His forehand is a bit hitchy and it is nowhere near as effective as his backhand. By my Forehand Potency metric (FHP), he earns barely any points off that wing, ranking among the likes of Adrian Mannarino and Mikael Ymer.

And then there’s the serve. While he is capable of firing bullets–one of his serves in Australia registered at 128 mph (208 kph)–he rarely goes that route. His first serves in Miami have hovered around 110 mph, so he sets up points with slices wide, especially in the deuce court. He manages a respectable ace total thanks to a well-disguised delivery and the surprise that comes from his occasional bombs down the T.

The Machac serve is not a liability, exactly, but it is not the standard first-strike weapon for a prospect in today’s men’s game. Let’s take a closer look.

Lean right

Aside from keeping an eye on the radar gun while watching Machac’s progress in Miami, I don’t have a lot of data to put his serve speed in context. The only available point-by-point serve speed data these days comes from Wimbledon and the US Open, where the Czech has played just two career main-draw matches.

At Wimbledon last year, Machac’s first serves clocked an average of 115 mph (184 kph), faster than about one-third of the field. The Wimbledon gun might have been a little hot, as most players scored better there than in New York, and by a wider margin than you’d expect from more serve-centered tactics. When the Czech played a match at the US Open in 2022, his average first serve speed was 107 mph (171 kph). Four-fifths of the field hit harder; most of the names in his part of the list are clay-courters. Presumably he has gotten stronger since then, so while 115 mph may be an overestimate, 107 mph is probably low.

These numbers confirm that the serve won’t hold him back too much. Some other men in the same neighborhood are Casper Ruud, Tommy Paul, and David Goffin. Neither Carlos Alcaraz nor Novak Djokovic averaged much faster than Machac on the Wimbledon gun last year, and they did just fine. The Czech has only a bit of ground to make up with the rest of his game, and Ruud offers one example that it can be done.

What makes Machac’s serve look so pedestrian is the frequency with which he spins wide serves in the deuce court. Against Murray yesterday, he hit 54% of his deuce-court firsts to the wide corner. Fewer than 40% went down the T, and most of the remainder were also to the forehand side. He was even more extreme in the ad court, spinning 61% of those first serves down the T to the opponent’s forehand.

60/40 sounds rather undramatic, like most tennis stats. But few men favor one direction so strongly, at least until they reach critical situations like break point, when they lean more heavily on their favorite angle. Machac tries to balance it out by aiming for the backhand with his second serves, though by a slightly narrower margin. That does the job: The gap between his first- and second-serve results is about the same as tour average.

In the deuce court, at least, the tactic is working. Against Murray yesterday, Machac won 18 of 22 (82%) when his first serve went wide, though he was nearly as successful down the T. Against Rublev, he won 13 of his 14 wide deuce-court first serves. Understandably, he didn’t hit many deuce-court serves anywhere else. When Murray broke back yesterday to keep the third set alive, it wasn’t the serve itself that let Machac down. Twice at deuce, the Czech missed first serves when he tried to go down the T. His wide second serves drew weak replies on both occasions, but he lost both points with unforced errors.

The dis-ad-vantage

Wide serves in the deuce court are a gamble. You let your opponent take a swing at a forehand–probably his preferred wing–but you pull him out of position. Clearly it can work. Few men rely more heavily on their forehand than Rublev does, yet Machac attacked that side at every opportunity.

Murray was cannier and kept things much closer than Rublev did. But even he was fighting a losing battle. Machac won 80% of total first-serve points in the deuce court yesterday, compared to 69% in the ad court. So far, the Czech’s opponents have been more like Murray than Rublev, but still, the serve-to-the-forehand gamble pays off.

While he likes to aim for the same wing in the ad court as well, Machac doesn’t get the same court-position advantage. Across ten matches logged so far by the Match Charting Project, he has won 78% first-serve points in the deuce court against 71% in the ad court.

The difference lies largely in what Machac can do with his plus-one shot. In the deuce court, he wins about half of first-serve points with his serve or plus-one. In the ad court, that number falls below 40%. 50% is excellent: Djokovic hardly does better than that, and even an imposing server like Ugo Humbert does worse. But 40% is dire. Only clay-courters win so few short first-serve points overall. There’s less room to put away the second shot when you’ve left the returner standing in the middle of the court.

There’s nothing inherently wrong with a split between deuce-court and ad-court results. If asked, most players would probably prefer to win more points in the ad court, since most break points start in that direction. But the effect of winning more break points is mostly cancelled out by earning fewer break chances in the first place. Anyway, Machac doesn’t have any particular problem saving break points. He survived 13 of 15 against Murray. At tour level since this time last year, he has saved 64.5% of break points faced while winning 65.5% of serve points overall. That’s a closer margin that most players can boast.

The deeper we dig, the more we find weaknesses and unusual preferences in Machac’s game. Paired with each one, it seems, is a way in which it could work to his advantage. So far, he has succeeded despite the oddities. His results against Rublev and Tiafoe suggest that stronger competition might not break the spell, though the demands of yesterday’s gutbuster with Murray makes me wonder if brainier competition will raise the bar.

As the men’s game gets ever more powerful, there is less room at the top for playing styles that break the mold. Machac has already hinted that he can counterbalance brute force with the right set of angles, especially if they create opportunities for him to deploy his top-tier backhand. Countryman Radek Stepanek cracked the top ten with his own brand of unorthodox unpredictability. Machac has a different set of quirks, but based on his rapid progress this year, he may be able to do the same.

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Welcome to the Show, Luciano Darderi

*Luciano Darderi in 2023. Credit: jmmuguerza*

Italian tennis hardly needs any more prospects, but Luciano Darderi has announced himself as yet another young player to watch. The Argentinian-born right-hander turns 22 today, three days after securing his debut ATP title. He came through qualifying in Cordoba, and in just his third appearance in a tour-level main draw, knocked out the 2nd, 4th, and 7th seeds en route to the championship.

Darderi is a supercharged clay courter, comfortable on dirt yet possessing a serve and forehand that will play on faster surfaces. He cracked 25 aces in the Cordoba main draw, plus another 11 in qualifying. On Sunday, fellow qualifier Facundo Bagnis got barely half of Darderi’s first serves back in play. Against Sebastian Baez in the semi-finals, the Italian ended 22 points with a forehand winner or forced error and, as we will see, held his own from the baseline against one of the game’s most stubborn defenders.

Though the magnitude of Darderi’s breakthrough came out of nowhere, he has been inching toward a double-digit ranking for some time. He reached 13 Challenger quarter-finals last year, advancing to three finals and collecting a pair of titles. He finished the year ranked 128th and gained 60 places with the victory in Cordoba, ensuring he’ll have plenty more chances to prove his mettle on tour.

He hasn’t hesitated to take advantage, dropping just three games in beating Mariano Navone in Buenos Aires yesterday. The victory extended the Italian’s winning streak to eight and shows just how fast he is developing, having lost to Navone in a bruising Challenger final just a few months ago.

It won’t always be so smooth for Darderi: The hard-court skew of the top level of the circuit may not prove hospitable to a youngster who has played 84% of his career matches on clay. Even with the right weapons in hand, it will take some time to become more than just a dark horse on the Golden Swing. But that’s all in the future: Darderi’s 22nd birthday is an ideal opportunity to dig into the upsets that lifted him from Challenger warrior to the top 100.

Bullying the little guy

The defining win of the Italian’s week in Cordoba was the semi-final. Baez struggled at the end of 2023, but he is always a tough out on clay, especially coming off a third-set-tiebreak victory in Davis Cup. At just five-feet, seven-inches tall, the Argentinian relies on speed and defense, neutralizing the weapons of larger men. It doesn’t always work–his serve puts him at an immediate disadvantage, and he can become overly aggressive and error-prone to compensate–but he doesn’t give much away.

Despite his size, Baez doesn’t mind going toe-to-toe with an opponent’s best shot. In 19 clay-court matches tracked by the Match Charting Project since the beginning of 2022, Baez’s opponents have hit forehands–excluding service returns–as 61% of their baseline shots, compared to a tour-wide clay-court average of 55%. Thomaz Bellucci found the forehand 72% of the time against the Argentinian; Tallon Griekspoor clocked in at 71%.

Both lost. No matter what the shot, if you find yourself in a rally with Baez, your odds aren’t good. When you hit a forehand after the service return, your chances of winning the point are 45%; with a backhand, your chances are 44%. (Tour averages on clay are 53% and 47%, respectively.) Some individual cases are downright comical. In the 2022 Bastad quarter-finals, Dominic Thiem won just 27% of points when he hit a forehand. When the two men met again in the Kitzbuhel final last year, Thiem relied a bit more on his backhand. Alas, he won only 14% of points when he hit one of those.

Darderi ran around a few backhands to find his bigger weapon, but he generally refused to take the bait. He waited for his spots to attack one of the toughest men on tour to be patient against. This table details the results he got from his forehands and backhands in the semi-final:

                   FH/GS  FH W%  FH Wnr%  FH UFE%  
Darderi vs Baez    55.4%  50.6%    12.2%     8.5%  
Average vs Baez    60.6%  45.2%    10.4%    12.0%  
                                                   
                   BH/GS  BH W%  BH Wnr%  BH UFE%  
Darderi vs Baez    44.6%  48.5%     6.1%     6.8%  
Average vs Baez    39.4%  43.8%     6.3%    10.3%

The Italian hit fewer forehands than the usual Baez opponent, and it won him more points, in part thanks to hitting winners at a higher rate and coughing up fewer unforced errors. His backhand numbers were favorable as well, perhaps in part because he set up for backhands in places where other opponents would go for an inside-out forehand. He was particularly stingy with free points on that wing.

Despite possessing the bigger gun, Darderi let his opponent make the mistakes. Baez obliged, piling up 32 unforced errors, including an uncharacteristic 11% of his backhands. Winning percentages of 50.6% and 48.5% hardly make for good headlines, but coupled with a big serve, they are enough to beat Baez. Few players on tour have been able to manage the same.

Tailored attack

The classic clay-court baseline weapon is the inside-out forehand, a salvo that might not end the point, but will pull the opponent out of position and leave the court open for a finishing blow. Darderi can win matches with that shot, as he did in the final against Bagnis. His left-handed opponent kept sending balls to his backhand corner, and the Italian ran around a lot of them. More than half of Darderi’s forehands in the final were inside-out, and he won the point 78% of the time he hit one. The match wasn’t close.

As we’ve seen, though, manufacturing forehands against Baez is a trap. The Argentinian can blunt the angle and absorb the pace, and meanwhile, his opponent is out of position. When Thiem had his terrible day in Bastad, he hit 62 inside-out forehands, only 16 of them in points that he won. (He typically wins more than half, as does the tour as a whole.) Whether by preparation or intuition, Darderi took those chances much less often, and far less frequently than he would against Bagnis. Just one in six of his forehands were of the inside-out variety, and he won just shy of half those points.

Instead, with Baez accustomed to playing defense on the backhand side, Darderi attacked to the forehand. While he didn’t go crosscourt particularly often, he hit hard when he did. 22% of his crosscourt forehands ended the point in his favor with a winner or forced error. That shot can be a slightly favorable play against Baez–opponents win 47% of those points, compared to 45% for forehands overall–but only Nicolas Jarry has cleaned up against Baez in this category the way that Darderi did. It’s way too early to draw any conclusions about how the Italian’s game will fare on tour, but when you share the top of a forehand leaderboard with Jarry, you’re doing something right.

A big serve and a forehand isn’t enough: Nearly everybody has those, even if Darderi’s forehand has a bit of extra mojo. Upsetting the forehand-neutralizing Baez, especially in between victories against less complicated opponents, is a sign that the Italian has resources between his ears as well. Every week, it seems, Italian tennis looks a little bit better.

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Podcast Episode 104: The Present and Future of Jannik Sinner

Episode 104 of the Tennis Abstract Podcast, with Carl Bialik of the Thirty Love podcast, is our recap of the Miami Open, with a particular focus on the Italian teenager who reached the final there.

Jannik Sinner has a relatively weak first serve, but seems to do everything else right. We talk about how to balance what he is with what he could be, the importance of his evident emotional maturity, whether he’ll eventually win more first serve points, how well he’ll fare on clay this year, and just how much we can compare him with Rafael Nadal.

We also discuss the man who beat Sinner in the Miami final, Hubert Hurkacz. Is a 24-year-old without any obvious elite-level weapons still on the rise, or will the Masters 1000 title mark his career peak?

Thanks for listening!

(Note: this week’s episode is about 58 minutes long; in some browsers the audio player may display a different length. Sorry about that!)

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

Podcast housekeeping:

The TAP book club will resume next week with Arthur Ashe’s memoir, Days of Grace. I’ve posted a few notes about Ashe and the book here. If you have thoughts or questions for us to consider, please let me know.
In case you haven’t heard, I’m 52 episodes into a short (~4 minute) daily podcast called Expected Points. Here’s today’s episode. I’m also doing a daily baseball podcast with the same format during the MLB season–check out The Opener.

Podcast Episode 102: Erik Jonsson on the Rising Wave of Stars in Men’s Tennis

Episode 102 of the Tennis Abstract Podcast welcomes back Erik Jonsson (@erktennis), previously heard on Episode 77 of the show in November of 2019.

Erik is a longtime Challenger and prospect watcher, and he shares his thoughts on Lorenzo Musetti, Aslan Karatsev, Jannik Sinner, Carlos Alcaraz, Sebastian Korda, and more. We talk about how to identify future tour-level stars by watching Challenger matches, whether there is any hope of another top-tenner as short as Diego Schwartzman, why Sweden hasn’t produced a female tennis superstar, what constitutes a legit top-20 player, and much more.

Thanks for listening!

(Note: this week’s episode is about 64 minutes long; in some browsers the audio player may display a different length. Sorry about that!)

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

Podcast housekeeping:

The TAP book club is reading Arthur Ashe’s memoir, Days of Grace. I’ve posted a few notes about Ashe and the book here, and we’ll talk about it in a podcast episode next month.
I’m 43 episodes into a short (~4 minute) daily podcast called Expected Points. Here’s today’s episode. I’m doing a daily baseball show, too!

Andreescu, Medvedev, and the Future According to Elo

With the US Open title added to her 2019 trophy haul, Bianca Andreescu is finally a member of the WTA top 10, debuting at fifth on the ranking table. Daniil Medvedev, the breakout star of the summer on the men’s side, only cracked the ATP top 10 after Wimbledon. He’s now up to fourth. The official ranking algorithms employed by the tours take some time to adjust to the presence of new stars.

Elo, on the other hand, reacts quickly. While the ATP and WTA computers assign points based on a year’s worth of results (rounds reached, not opponent quality), Elo gives the most weight to recent accomplishments, with even greater emphasis placed on surprising outcomes, like upsets of top players. If your goal in using a ranking system is to predict the future, Elo is better: Elo-based forecasts significantly outperform predictions based on ATP and WTA ranking points.

Andreescu’s first Premier-level title came at Indian Wells in March, when she beat two top-ten players, Elina Svitolina and Angelique Kerber, in the semi-final and final. The WTA computer reacted by moving her up from 60th to 24th on the official list. Elo already saw Andreescu as a more formidable force after her run to the final in Auckland, so after Indian Wells, the algorithm moved her up to seventh. Three more wins in Miami, and the Canadian teen cracked the Elo top five.

Tennis fans are accustomed to the slow adjustments of the ranking system, so seeing a “(22)” or a “(15)” next to Andreescu’s name at Roland Garros and the US Open wasn’t particularly jarring. And there’s something to be said for withholding judgment, since tennis has had its share of teenage flashes in the pan. But Elo is usually right. The betting market heavily favored Serena Williams in the US Open final, but Elo saw the Canadian as the superior player, giving her a slight edge. After the latest seven match wins in New York, the algorithm rates Andreescu as the best player on tour, very narrowly edging out Ashleigh Barty. Would you dare disagree?

The launching (Ar)pad

When Medvedev first reached the top ten on the Elo list last October, I ran some numbers to compare the two ranking systems. Most players who earn a spot in the Elo top ten eventually make their way into the ATP top ten as well, but Elo is almost always first. On average, the algorithm picks top-tenners more than a half-year sooner than the tour’s computer. The 23-year-old Russian is a good example: He reached eighth place on the Elo list last October, but didn’t match that mark in the ATP rankings for another 10 months, after reaching the Montreal final.

Andreescu closed the gap faster than Medvedev did, needing a more typical six months to progress from Elo top-tenner to a single-digit WTA ranking. It may not take much longer before her Elo and WTA rankings converge at the top of both lists.

We no longer need Elo to tell us that Andreescu and Medvedev are likely to keep winning matches at the highest level. But having acknowledged the accuracy with which Elo glimpses the future, it’s worth looking at which players are likely to follow in their footsteps.

After the US Open, Elo’s boldest claim regards Matteo Berrettini, ranked sixth. The ATP computer sites him at 13th, and he only made one brief stop this summer inside the top 20. The Flushing semi-finalist has been inside the Elo top 10 since mid-June, and the algorithm currently puts him ahead of such better-established young players as Alexander Zverev and Stefanos Tsitsipas.

The women’s Elo list doesn’t feature any similar surprises in the top 10, but that hardly means it agrees with the WTA computer. Karolina Muchova, currently at a career-high WTA ranking of 43rd, is 23rd on the Elo table. Two veteran threats, Victoria Azarenka and Venus Williams, are also marooned outside the official top 40, but Elo sees them as 18th and 28th best on tour, respectively. In terms of predictiveness, quality is more important than quantity, so a limited schedule isn’t necessarily seen as a drawback. Elo is also optimistic about Sofia Kenin, rating her 13th, compared to her official WTA standing of 20th.

Half a year from now, I’d bet Berrettini’s official ranking is closer to 6 than to 13, and that Muchova’s position is closer to 23 than 43. It’s impossible to tell the future, but if we’re interested in looking ahead, Elo gives us a six-month head start on the official rankings. We’ll have to wait and see whether the rest of the women’s tour can keep Andreescu away from the top spot for that long.

How Good is Cori Gauff Right Now?

Italian translation at settesei.it

15-year-old sensation Cori Gauff holds a WTA ranking of No. 313. She has played only a limited number of events that are considered by the WTA’s system, so even before her impressive run began, we could’ve predicted that her ranking was an understatement. But by how much?

Gauff doesn’t show up yet on my Elo ratings list because, before Wimbledon qualies, she hadn’t played at least 20 matches at the ITF $50K level or higher in the last year. However, she still had a rating: 1,488, good for 194th place among those who had met the playing time minimum. A rating in that range translates to about a 3% chance of upsetting current top-ranked player Ashleigh Barty, and a 10% chance of beating someone around 20th, such as Donna Vekic. Given how little data we had to work with at that point, that seemed like a reasonable assessment.

Since she arrived in London, she has won six matches: Three in qualifying and three in the main draw, with wins over Venus Williams, Magdalena Rybarikova, and Polona Hercog. Not bad for a teenager who had previous won only one slam qualifying match and one tour-level main draw match in her young career!

194th place doesn’t seem like such a fair judgment anymore. Any player who comes through qualifying and reaches the fourth round at a major deserves some reassessment, and that’s even more applicable to a player about whom we knew so little two weeks ago. The tricky part is figuring out how much to adjust. Is Gauff now a top-100 player? Top 50? Top 20?

Revising with Elo

The Elo algorithm does a good job of approximating how humans make those reassessments: The more data we already have about a player, the less we will adjust her rating after a win or loss. The previous player to defeat Hercog was Simona Halep, at Eastbourne. We already have years’ worth of match results for Halep, and she was heavily favored to win the match. Thus, the fact that she recorded the victory alters our opinion of her by only a small amount. In Elo terms, it was an increase from 2,100 points to 2,102–basically nothing.

Gauff is a different story. Entering her third-round clash with Hercog, not only did we know very little about her skill level, it wasn’t even clear if she was the favorite. The result caused Elo to make a considerably larger adjustment, increasing her rating from 1,713 to 1,755, a rise 21 times greater than what Halep received after beating the same opponent. The 42-point jump caused her to leapfrog 16 players in the rankings.

Here is Gauff’s Elo progression, from the moment she arrived at Wimbledon to middle Sunday. After each match, I show her overall Elo (the numbers I’ve been discussing so far), her grass-specific Elo, and her grass-weighted Elo, a 50/50 blend of overall and grass-specific that is used for forecasting. For each of the three ratings, I also show her ranking among WTA players with at least 20 matches in the last 52 weeks.

Match          Overall   Rk  Grass   Rk  Weighted   Rk  
Pre-Wimbledon     1488  194   1350  163      1419  187  
d. Bolsova        1540  171   1405  132      1473  155  
d. Ivakhnenko     1566  157   1447  107      1507  131  
d. Minnen         1614  132   1514   57      1564   95  
d. Venus          1670  108   1578   40      1624   73  
d. Rybarikova     1713   83   1650   21      1682   41  
d. Hercog         1755   67   1686   17      1721   31

Over the course of only six matches, Gauff has jumped from 194th in the overall Elo rankings to 67th. For forecasting purposes, her grass court rating has soared from 187th to 31st. Her current weighted rating of 1,721 is better than that of three other women in the round of 16: Karolina Muchova, Carla Suarez Navarro, and Shuai Zhang. She trails another surviving player, Elise Mertens, by only 20 points.

So you’re telling me there’s a chance

Unfortunately, none of those relatively weak grass-court players are Gauff’s next opponent. Instead, the 15-year-old will face Halep, the third-best remaining player (behind Barty and Karolina Pliskova), and a three-time quarter-finalist at the All England Club. Halep’s weighted Elo rating is 229 points higher than Gauff’s, implying that the veteran has a 79% chance of winning on Monday. The betting market concurs, suggesting that the probability of a Halep victory is about 80%.

It doesn’t usually have much of an effect on forecasts to update Elo ratings throughout a tournament. While anyone reaching the 4th round has a higher rating than they did before the event, the differences are typically small. And since forecasts are based on the difference between the ratings of two players, the forecast isn’t affected if both players’ ratings have increased by roughly the same amount.

As a teenager with such limited match experience, Gauff breaks the mold. Her pre-Wimbledon 1,488 Elo rating is only two weeks old, and it is already completely unrepresentative of what we know of her skill level. She’ll have ample time to prove us right or wrong in the upcoming years, but for now, we have good reason to estimate that she belongs–even more than some of the older players who have reached the second week at Wimbledon.

Forecasting Future Felix With ATP Aging Patterns

Italian translation at settesei.it

It’s been an exceptional six weeks for Felix Auger-Aliassime. He broke into the top 100 with a runner-up performance on clay in Rio de Janeiro, won two matches each at Sao Paulo and Indian Wells (including an upset of Stefanos Tsitsipas), and raced to a semi-final at the Miami Masters, the youngest player ever to make the final four of that event. Four months away from his 19th birthday, his ranking is up to 33rd in the world, and he has few points to defend until June.

Felix is the youngest man in the top 100, and he’s reaching milestones early enough to draw comparisons with some of the best young players in the sport’s history. Will he follow in the footsteps of past wunderkinds such as Rafael Nadal and Lleyton Hewitt? To answer that question, let’s take a look at typical ATP aging patterns, what they say about when players hit their peaks, and what they can show us about the fate of the best 18 year olds.

The standard curve

Last week, I looked at WTA aging curves and found that women tend to peak around age 23 or 24, an age that has not changed even as the sport has gotten older. I also discovered that there is a surprisingly modest gap–about 70 Elo points–between 18-year-old performance and a woman’s peak level. The men’s results are different.

To calculate the average ATP aging curve, I found over 700 players who were born between 1960 and 1989 and played at least 20 tour-level, tour qualifying, or challenger-level matches in each of five seasons. Overall, peak age was 25, though the difference from age 24 to 27 is only a few Elo points, so small as to be negligible.

As the tour has gotten older, the men’s peak age has also increased. Of the nearly 300 players born between 1980 and 1989, peak age is 26-27, with ages 28 and 29 also within 10 Elo points of the age 26-27 peak. Plenty of players are peaking at older ages, and many of those who aren’t are remaining close to their best levels into their late twenties. The peak age could be even higher still–a few of the players in the 1980-89 cohort turn 30 this year, and could conceivably still improve on their career bests.

The following graph shows the trajectory of the average player (with peak year-end Elo set to 1,850) born in the 1960s and the pattern of the average player born in the 1980s:

It’s a long ascent from the performance level at age 18 to the typical peak, especially for more recent players. There’s even a hefty bit of selection bias that should inflate the level of 18 year olds, since only about 10% of the players in the overall sample qualified for a year-end Elo rating when they were 18. The ones who did were, in general, the best of the bunch.

Felix forward

Through the Miami semi-final, Auger-Aliassime’s Elo rating is 1,848. The average player in the entire dataset who played at least 20 matches in their age-18 season went on to add another 281 Elo points to their rating between the end of their age-18 season and their peak. In the narrower, more recent cohort of 1980-89 births, the players with year-end ratings as 18 year olds improved their Elos by a whopping 369 points before reaching their peaks.

Adding either of those numbers to Felix’s current rating gives us quite the rosy forecast:

Cohort   Current  Increase  Proj. Peak  
1960-89     1848       281        2129  
1980-89     1848       369        2217

There’s a bit of slight of hand in how I’m doing this, since my study uses players’ year-end ratings, and I’m using Felix’s rating in April. However, there’s no natural law that says one artificial 12-month span is better than another, and Felix’s current age of 18.6 is roughly in the middle of the ages of the year-end 18-year-olds with whom I’m comparing him.

An Elo rating of 2,129 would be good enough for fourth place on the current list, behind only the big three. The rating of 2,217 is better than any of the big three can boast at the moment, and would be the fourth-best peak year-end rating among active players, again trailing only the big three. (And Andy Murray, if you consider him active.) Only 15 Open era players have managed year-end Elo peaks above 2,217.

No comparisons

It’s tough to say whether this method, of finding the typical difference between 18-year-old and peak Elo ratings, is adequate to handle the extremes. Some players peak earlier than average, and it stands to reason that the best young talents are more likely to do so. Boris Becker posted a whopping 2,212 Elo rating at the end of his age-18 season, which didn’t leave much room for improvement. He gained another 90 points before the end of his age-19 season, which was his career best.

Becker’s career path is not particularly helpful to our effort to forecast Felix’s, in part because the German was so unique, and also because his experience reflects such a different era. But even among less unique players, there are few useful comparables. No one born since 1987 managed a better age-18 Elo rating than Felix’s 1,848, and only a handful of active or recently-retired players even reached 1,750 by that age.

Lacking the data for a more precise approach, let’s repeat what I did for Bianca Andreescu last week, and see how the nearest 18-year-old comparisons fared. Of the players whose age-18 year-end Elos were closest to Felix’s 1,848, here are the 10 above him and the 10 below him on the list:

Player               BirthYr  18yo Elo  Incr  Peak Elo  
Stefan Edberg           1966      1916   350      2266  
John Mcenroe            1959      1912   496      2408  
Guillermo Coria         1982      1909   145      2055  
Pat Cash                1965      1907   151      2058  
G. Perez Roldan         1969      1884    41      1925  
Andy Murray             1987      1878   465      2343  
Roger Federer           1981      1871   487      2359  
Thomas Enqvist          1974      1865   216      2081  
Rafael Nadal            1986      1862   452      2314  
Jim Courier             1970      1849   283      2132  
…                                                       
Jimmy Brown             1965      1834     0      1834  
Andy Roddick            1982      1815   291      2106  
Aaron Krickstein        1967      1812   246      2058  
Yannick Noah            1960      1812   299      2112  
Fabrice Santoro         1972      1805    85      1890  
Andreas Vinciguerra     1981      1803    16      1819  
Novak Djokovic          1987      1792   645      2436  
Sergi Bruguera          1971      1790   265      2055  
Thomas Muster           1967      1788   329      2117  
Dominik Hrbaty          1978      1779   133      1913

The average increase among this group is 270 Elo points, close to the overall average for players who qualified for a year-end Elo rating at age 18. The youngest members of this list are encouraging: the big four, Andy Roddick, and Andreas Vinciguerra. Most promising youngsters would happily take a two-in-three shot at having a career at the level of the big four.

Perhaps the best comparison for Felix is a player who didn’t quite make that list, Alexander Zverev. The 21-year-old German posted a year-end Elo of 1,768 as an 18 year old, and already boosted that number by more than 300 points at the end of his 2018 campaign. Zverev is only an approximate comparison, he’s just a single data point, and we don’t know where he’ll end up, but his experience is a decade more recent than those of Novak Djokovic, Murray, and Nadal.

Forecasting the career performance of young tennis players is an inexact science, at best. Potential outcomes for Auger-Aliassime range from teenage flameout to double-digit major winner. Based on the limited information he’s given us so far, the latter seems within reach. What we know for sure is that he’s playing better tennis than any 18 year old we’ve seen in a decade. If that’s not reason for optimism, I don’t know what is.

Denis Shapovalov and Fast ATP Starts

Italian translation at settesei.it

18-year-old Canadian lefty Denis Shapovalov has had one heck of a summer. In Montreal, he defeated Juan Martin del Potro and Rafael Nadal in back-to-back matches, and at the US Open, he qualified for the main draw, upset Jo Wilfried Tsonga, and reached the fourth round in only his second appearance at a major.

Thanks to those wins and the big stages on which he achieved them, he has cracked the ATP top 60, despite playing fewer than 20 tour-level matches. The Elo rating system, which awards points based on opponent quality, is even more optimistic. By that measure, with his win over Tsonga, Shapovalov improved to 1950–good for 34th on tour–before losing about 25 Elo points in his loss to Pablo Carreno Busta.

While an Elo score of 1950 is an arbitrary number–there’s nothing magical about any particular Elo threshold; it’s just a mechanism to compare players to each other–it gives us a way to compare Shapovalov’s hot start with other players who made quick impacts at tour level. Since the early 1980s, only 13 players have reached a 1950 Elo score in fewer matches than the Canadian needed. As usual with early-career accomplishments, there are a few unexpected names in the mix, but overall, it’s very promising company for an 18-year-old:

Player               Matches   Age  
Lleyton Hewitt             7  16.9  
Jarkko Nieminen            7  20.2  
Juan Carlos Ferrero       10  19.4  
David Ferrer              12  20.4  
Kenneth Carlsen           12  19.4  
Tommy Haas                13  19.1  
Peter Lundgren            13  20.7  
John Van Lottum           14  21.8  
Sergi Bruguera            14  18.4  
Julian Alonso             15  20.0

Player               Matches   Age   
Xavier Malisse            16  18.6  
Jan Siemerink             16  20.9  
Ivo Minar                 16  21.2  
Florian Mayer             17  20.7  
Cristiano Caratti         17  20.7  
Nick Kyrgios              17  19.3  
Denis Shapovalov          17  18.4  
Martin Strelba            17  22.1  
Jay Berger                17  20.2  
Andy Roddick              18  18.6

I identified just over 350 players who, at some point in their careers, peaked with an Elo score of at least 1950. On average, these players needed 75 matches to reach that level (the median is 59), and two active tour-regulars, Gilles Muller and Albert Ramos, needed almost 300 matches to achieve the threshold.

Shapovalov’s record so far is equally impressive when we consider it in terms of age. Again, he’s among the top 20 players in modern tennis history: Only 11 players got to 1950 before their 18th birthday. The Canadian is only a few months beyond his. And many of the other ATPers who reached that score at an early age needed much more tour experience. I’ve included the top 30 on this list to show how Shapovalov compares to so many of the game’s greats:

Player                  Matches   Age  
Aaron Krickstein             25  16.4  
Michael Chang                32  16.5  
Lleyton Hewitt                7  16.9  
Boris Becker                 27  17.5  
Mats Wilander                27  17.5  
Guillermo Perez Roldan       26  17.6  
Andre Agassi                 46  17.6  
Pat Cash                     66  17.6  
Goran Ivanisevic             35  17.7  
Andrei Medvedev              22  17.8  

Player                  Matches   Age
Rafael Nadal                 44  17.9  
Sammy Giammalva              21  18.0  
Horst Skoff                  19  18.1  
Jimmy Arias                  61  18.2  
Kent Carlsson                56  18.3  
Sergi Bruguera               14  18.4  
Denis Shapovalov             17  18.4  
Andy Murray                  22  18.4  
Juan Martin del Potro        31  18.4  
Fabrice Santoro              59  18.5  

Player                  Matches   Age
John McEnroe                 28  18.5  
Roger Federer                40  18.5  
Stefan Edberg                40  18.5  
Andy Roddick                 18  18.6  
Pete Sampras                 56  18.6  
Thomas Enqvist               28  18.6  
Xavier Malisse               16  18.6  
Novak Djokovic               33  18.8  
Jim Courier                  51  18.8  
Yannick Noah                 41  18.8

There are no guarantees when it comes to tennis prospects, but this is very good company. On average, the 23 other players to reach the 1950 Elo threshold at age 18 improved their Elo ratings to 2100 before age 20, and rose to 2250 at some point in their careers. The first number would be good for 12th on today’s list, and the second would merit 5th place, just behind the Big Four. Nadal and del Potro were the first of Shapovalov’s high-profile victims, and judging from this sharp career trajectory, they won’t be the last.

First Look: Francis Tiafoe

Last night at the Citi Open in Washington, Francis Tiafoe played his first tour-level main draw match. For a 16-year-old with almost no professional experience, he put on a good show, making Evgeny Donskoy work hard for his 6-4 6-4 victory.

Tiafoe is one of a few young American men viewed as rising stars. He doesn’t have the professional experience of Stefan Kozlov or Jared Donaldson, but he has nonetheless racked up some impressive feats in the last eight months, claiming the title at the Orange Bowl in December and another big win at the Easter Bowl in April.

His game, as viewers discovered last night, is a work in progress. He lit up the radar gun with both serves and forehands, but neither was steady enough to avoid getting broken by Donskoy three times. His backhand, the less showy but more consistent half of his ground game, was sufficiently solid to keep him in points, but it aside from a couple of down-the-line bullets, it was rarely enough to win them.

Both serve and forehand are, at this stage of his development, very complicated shots. His serve is a bit jerky, and his second serve is particularly erratic. A more offensive kick serve would do wonders for his service game–he won barely 40% of second-serve points yesterday.

The forehand is an even bigger problem. It’s easy to get fooled by the occasional big winner–he did hit some sensational shots from that wing last night. The bigger picture, though, is that his big, not-very-fluid windup prevents him from hitting the effective rallying shots that are absolutely necessary to compete at this level. Compared to top-100 players, Donskoy is not a particularly tough test, and Tiafoe hit 19 unforced errors from that side alone. That’s 20% of his total forehands in the match–double the tour-average rate of forehand unforced errors. They also accounted for one-third of all the points he lost.

It could have been worse. Donskoy, whether because he feared the forehand or because he stuck with familiar patterns, tended to rally back to Tiafoe’s backhand. That shot is far smoother, simpler, and much, much more consistent. While he didn’t try for nearly as much off that wing, he did hit four winners–and only four unforced errors.

He tended to play far behind the baseline, so it was a rare point that displayed other aspects of his game. In the second set, he opted for a few more slice backhands, a shot he seemed to have a decent feel for. He hit one very slick backhand drop shot for a winner, but more often when he ventured inside the baseline, he didn’t appear to have a natural sense for smart, reasonably-high-percentage plays.

It’s important to keep all this in perspective, though. Tiafoe is the youngest man to play an ATP main-draw match this year–nine months younger than Alexander Zverev, for instance. Donskoy was his first top-300 opponent and last night was only his 15th professional match. If he didn’t look particularly poised rushing between points, I think we can let it slide.

As strong a player as Tiafoe is for his age, the inconsistency of both serve and forehand will likely keep him out of the spotlight for another few years. Unlike Zverev and Borna Coric, he won’t be challenging top-50 players before his 18th birthday. Still, there are a lot of good qualities to build on, and when he hits his twenties, he could well be part of the next great generation of American players on the ATP tour.