Tennis' Top 20 Under 20: 4th Edition

A year and a half ago, I posted a ranking of the 20 best teenagers on the ATP at the time, and have since posted two other updates to the list, taking into consideration the new results.  This is now the fourth edition of the series that takes a look into the future of the ATP and it's stars. This is not a ranking of their current form (there is already a computer ranking for that), but rather a ranking of what their future form could be.

The dynamic of teenagers in tennis has changed drastically over the last two years, which is what prompted me to start compiling this list of teenagers. Just a few years ago, there were several consecutive months, where there wasn't a single teenager ranked in the top 200. However, this new crop of teenagers hasn't been so shy to break through with a total of 11 teenagers now in the top 200 and four in the top 100. When making this list, I started with over 30 players, analyzing their results and watching videos on YouTube to find the best 20 out of the group. The analysis is based far more on the results, but that alone certainly doesn't tell the whole story. Anyways, let's get started.

This is my list of the 20 most promising talents in tennis that are under 20 years old.

1. Alexander Zverev (GER) Age: 18, Rank 70

Zverev has bounced around this list going from second to sixth to third and now finally is at the top of the list. Finding the German at the top of the list right now might be surprising since his only main draw win in his last eight events before February came against a player ranked outside the top 500. However, last week, he came out of that slump with an impressive straight-set victory over Marin Cilic. He then backed that up with a win over Gilles Simon to reach the quarterfinals in Rotterdam. Zverev has a big game, which works on all surfaces and as a 6-foot-6 player it is going to take him a little while longer than others to learn how to reach the peak of his abilities. He's now at a career-high ranking of No. 70 in the world and still has a ton of room to grow.

2. Borna Coric (CRO) Age: 19, Rank 38

This list is not the only one where Coric is moving in the wrong direction. The Croat has begun to drop in the rankings, while suffering a four-match losing streak since reaching the final in Chennai. Still, reaching a tour-level final is one of the best results that any teenager can boast right now. Coric is also the highest ranked teenager. The Croat is an incredible shot-maker with great movement and has the ability to take returns from far inside the baseline. His forehand is his biggest weapon, but there are plenty of teenagers that have bigger forehands, so his path to success won't be as straightforward. If he can continue to become a more complete player, he could be the best player of his era.

3. Taylor Fritz (USA) Age: 18, Rank 145

The improvement of Fritz over the past 12 months has not been gradual at all. He went from not on this list when it first came out two years ago to 14th and then to seventh. He's now third on the list largely because of what he has done since the 2015 US Open. In Sacramento, Fritz sealed his place atop the list of promising young Americans with a three-set win over Jared Donaldson in the final. Fritz immediately backed that up with a title in Fairfield without dropping more than four games in any set. This year, Fritz won the Happy Valley Challenger, qualified for the Australian Open, and defeated No. 2 seed Steve Johnson in Memphis. All of this is from a player who may have been the No. 1 junior player in the world a year ago, but on the tour-level was still outside the top 1000. The rapid progress for Fritz has been fun to watch, but his game is just as impressive, playing a similar style to many of the other teenagers that have had big breakthroughs, using his ground strokes off both wings as his main weapons, while sporting a rapidly improving serve that is more worthy of his 6-foot-4 frame.

4. Frances Tiafoe (USA) Age: 18, Rank 176 

Tiafoe is the only player born in 1998 or later that is ranked inside the top 200. In fact, only one player inside the top 300 is younger. Tiafoe is already one of the fastest players on tour with incredible feel around the net. His serve and ground strokes are far from ideal from a mechanical perspective, but that hardly matters with the athleticism Tiafoe has on the court. Tiafoe has reached the quarterfinals of his last two Challenger events and also has claimed impressive wins over Jared Donaldson and Sam Groth, defeating both of them 6-3, 6-3. Tiafoe doesn't have nearly as much match experience on the clay, but it's possible that as he develops, clay could end up being his best surface.

5. Felix Auger Aliassime (CAN) Age: 15, Rank 738

Auger Aliassime just turned 15 and a half, but he is already turning heads with his results both on the junior circuit and professional tour. He is 11-3 in his career as a professional, which includes a bagel set over Gonzalo Lama, who is in the top 300 in the world. He also won the first set against Japanese prodigy Yoshihito Nishioka, who is four years older. As a junior, he has already climbed to No. 8 in the world thanks to the title he won at the Eddie Herr International Tennis Championships, which featured some of the best juniors in the world. The Canadian has fantastic technique on all of his shots and is extremely athletic for being 15 years old. He is the kind of kid that would be a top college recruit in any sport he wants, but chose to dedicate himself to tennis. If he keeps this up, he could become one of the youngest players to do a lot of things on the tour-level.

6. Hyeon Chung (KOR) Age: 19, Rank 69 

This is Chung's final opportunity to appear on this list before he turns 20 in May. In the past, his inability on the clay courts held him down a few spots on this list, but he now has two tour-level clay court wins in just two tournaments played on the dirt and also has won a challenger title on clay despite only playing three clay tournaments at that level in his career. Chung was knocking on the door of the top 50 recently, but as the points he earned last January fell off, his ranking took a hit. He is now on the bubble for entrance at many of the ATP World Tour stops, so he may be bouncing back and forth between the two tours for a while. Chung has a very unique playing style, but like most players on this list, he stays away from the net and does his work from the baseline. Chung has better touch than most players on the list, so he could certainly develop into a great net player, which could be a very rare asset in a decade.

7. Andrey Rublev (RUS) Age: 18, Rank 150

This is the lowest that Rublev has appeared on this list in the year and a half of putting together this ranking. It has been a tough 2016 season for the Russian, who just lost in the first round of qualifying in Memphis to Radu Albot. Russian players have never been easy to predict, so the recent slump does cause concern, but Rublev is still one of the most talented teenagers in tennis. Rublev plays with his emotions on full display. He will likely tone that down as he gets older, but I don't think it will ever go away completely. He hits his forehand with a wide open stance, but on the backhand side closes his stance completely. His serve is very good, but because of the way he waits for balls on his ground strokes, if it isn't an unreturned serve, it's only useful for starting the point.

8. Jared Donaldson (USA) Age: 19, Rank 159 

Similar to Rublev, Donaldson has been in a slump recently resulting in a lower ranking on this list. Donaldson's ranking has basically been stuck where it is now since May of last year. However, this isn't the first time his ranking has gotten stuck. Starting in September 2013, his ranking moved relatively little for a six-month stretch. He bounced back nicely from that spell, so there is no reason to think he can't do it again. Donaldson is accomplished on all three surfaces. On his forehand, the American takes his left hand off the neck of the racket very early to set up, so when time is taken away on his forehand, it becomes a much weaker shot. When moving to his forehand he tends to finish above his head and drop the ball short or go for broke. Very few players on the Challenger Tour can put Donaldson on the defensive, but right now, that aspect of his game is holding him back. His second serve is where there is still a lot of room to improve and it definitely will improve. He'll be inside the top 100 soon enough.

9. Roman Safiullin (RUS) Age: 18, Rank 979

It's not normal to talk about 18-year old tennis players making a "comeback," but that's exactly what Safiullin is trying to do right now. The Russian was out of tennis for nearly an entire year and is now starting over at the lower levels. Safiullin had a great junior career and last January looked to be a very promising talent before an injury sidelined him. He has only won one match in his comeback, beating an unranked player 6-0, 6-0 in the first round of a futures event. His two losses have come against 20-year old Miki Jankovic, who not long ago was Serbia's hope to be a successor to Novak Djokovic, and 18-year old Seong-chan Hong, who narrowly missed a spot on this list. Putting Safiullin at No. 9 is purely a guess. There is no way to know what to expect. It will be very interesting to follow his results in the upcoming months.

10. Thanasi Kokkinakis (AUS) Age: 19, Rank 96

Kokkinakis is currently away from the tour for now with a shoulder injury and as always in tennis, it is hard to know exactly when he will be back. He made a point of saying that the surgery was because he wants to be better off long term, which is good to hear. Still, an injury at this stage in a player's career can be very damaging. Take for example Ricardas Berankis. Kokkinakis has a lot of weapons to play great offensive tennis as he showed against Novak Djokovic in Roland Garros. However, he is 6-foot-5 which isn't tall enough to follow the pattern of an Ivo Karlovic or John Isner, yet his numbers on return aren't much better, breaking serve only 15% of the time. Meanwhile, he only holds serve 79% of the time. Only five players finished in the top 50 in 2015 with a worse break percentage than Kokkinakis and each of them held serve at least 86% of the time.If Kokkinakis ever wants to be a top 50 player, he will have to make massive improvements to his return game.


11. Elias Ymer (SWE) Age: 19, Rank 153

Ymer has had some great results on both clay and hard courts already in his career and got through qualifying at all four slams last year. He's the kind of player that can have great results on a weekly basis regardless of where he is playing. Clay is certainly his best surface though, winning all six of his professional titles on that surface. He even eliminated Nick Kyrgios from Barcelona last year. However, he has also beaten Benoit Paire and Hyeon Chung on hard courts and even this year got through qualifying in Montpellier with a three-set win over fellow 19-year old Karen Khachanov, who is ranked exactly one spot higher. Ymer tends to play far behind the baseline and can hit some incredible winners from so far away, but his style of play tends to be to grind down his opponents on their serve, while holding quickly with a very efficient serve of his own.

12. Noah Rubin (USA) Age: 19, Rank 244

Rubin has been in and out of this list over the last two years and his decision to go to college really killed the hype for Rubin. However, he has proven that he absolutely made the right decision, spending a year at Wake Forest. The Long Island native has had an excellent start to the 2016 season resulting in being ranked 102 in the world in the Race Rankings despite only playing three tournaments so far this year. Rubin started the year with a win over Alex De Minaur, who is a top 10 junior player that very narrowly missed a spot on this list. He then upset world No. 18 Benoit Paire in straight sets in the first round of the Australian Open. He added three more impressive victories right after that, defeating Thibaud Berland, who is the No. 6 player in NCAA Division II right now. He then defeated Mitchell Krueger, who is coming off the best season of his career. He also added a win over Ernesto Escobedo, who would have been on this list if it were just a couple spots longer. Rubin has incredible horizontal speed on the baseline and possesses very compact and efficient ground strokes. When he steps onto the court, his game plan is clear and he will never beat himself.

13. Oliver Anderson (AUS) Age:17, Rank 650

The Australian summer was good to Anderson. The 17-year old won the Australian Open boys singles draw and even had a win in qualifying of the men's singles draw. Anderson also defeated both Tim Smyczek and Dennis Novikov in three sets in qualifying for Brisbane. Long before the 2016 season, Anderson made waves on the junior ranks with a run to the title on the clay court tournament in Castricum, Netherlands in 2013. He went through qualifying and didn't drop a single set all week, including in his 6-3, 6-3 win over Spaniard Juame Munar, who is now the best young gun in Spanish tennis. Still, he considers clay to be his weakest surface. Before 2016, Anderson had really struggled to find success on the professional level. His inability to win tiebreakers really hurt him, and continues to be somewhat of a problem. However, that will likely go away with experience. He is only 5-foot-9, which may stop him from ever being a dominant force on tour, but he is still growing and there are plenty of players under six feet tall that have had success in tennis.

14. Karen Khachanov (RUS) Age: 19, Rank 152

The Russian finally makes his debut on this list at the last possible time after narrowly missing the final cut in each of the last two editions. Khachanov finished 2015 with a career-high ranking of No. 151 and already claimed an impressive 6-3, 6-2 win over Kimmer Coppejans in Australian Open qualifying this year. The 6-foot-6 Russian took a little longer to develop his game, but when he put it all together in 2015, he was unstoppable. Khachanov's most impressive result was his run to the title at the Istanbul Challenger, defeating Sergiy Stakhovsky in the final, coming back from down a set. Khachanov never puts his left hand on the racket before hitting his forehand, which looks like a whip. He also uses very little of his lower body on the shot, which makes it just as good on the run. Since he tends to whip the forehand, it doesn't matter how much or little pace he is receiving. The backhand at times can also be a big weapon, but is clearly the weaker of his two ground strokes, meaning he runs around his it a lot. As you would expect of a 6-foot-6 player, he has a fantastic serve. It's very easy to compare Khachanov with a Jack Sock or Milos Raonic.

15. Rayane Roumane (FRA) Age: 15, Rank 944

2014 Les Petits As Champion Rayane Roumane may be the youngest of a large group of up-and-coming Frenchmen, but he certainly has the most promise at this point. Though he is barely 15-years old, he already has 10 main draw professional victories and is inside the top 1000. His most impressive win to date with a three-set victory over Jan Mertl, who has been lodged inside the top 500 of tennis since he first got in over 11 years ago. Roumane stands at 6-foot-3 and looks much older than just 15. Sometimes it can be hard to tell if someone is just an early bloomer or a true rising star. Roumane has skipped the junior tour completely and gone straight to being a professional player, so we will find out sooner rather than later.

16. Stefanos Tsitsipas (GRE) Age: 17, Rank 465

Comparing young players to Roger Federer is probably done more than it should be these days, but with Tsitsipas, it is very hard to miss the comparison to what Federer was like in his younger days. Tsitsipas has all the variety of Federer on the backhand side, he's smooth and the forehand side, has an abbreviated service motion, and is always looking to get to the net. Those were the qualities of Federer when he was a 17-year old. However, Federer eventually learned how to also become a great player from the baseline and developed one of the most efficient serves for a player his size. If Tsitsipas can develop the way Federer did, he will be a great player on tour. For now, he is a lot of fun to watch, but still has a ton of development to do to start beating other players on this list. His potential is still very high, but we are a long way away from seeing that potential reached.

17. Miomir Kecmanovic (SRB) Age: 16, Rank 1357

Kecmanovic is just over a year older than Roumane and he reached the final of the 2013 Les Petits As. However, he has gone a different path, playing mainly on the junior tour, while entering the main draw of just five futures events, where he has gathered four wins - two on clay and two on hard. He has been much more successful on the junior tour, becoming the first player born in 1999 in the top 100 and then quickly climbing to the No. 4 ranking. He has wins over Alex De Minaur, Stefanos Tsitsipis, Ulises Blanch, Ryan James Storrie, Casper Ruud, and Corentin Denolly. His build and playing style are both very comparable to Ryan Harrison. Hopefully he doesn't reach his peak quite as early as the American.

18. Quinten Halys (FRA) Age: 19, Rank 172 

Most of the tennis world was introduced to Halys when he took a beating from World No. 1 Novak Djokovic in the second round of the Australian Open this year, but the Frenchman actually is one of the rising talents on tour. Halys reached the quarterfinals of a pair of Challenger Tour events before getting into the main draw of the first slam with a wildcard, beating Ivan Dodig in the first round. Just before the Happy Slam, Dodig had reached the final of Canberra and the week before, in Brisbane had wins over Oliver Anderson, Jared Donaldson, Omar Jasika, showing his dominance over the next generation. Halys defeated Daniel Evans in the final of the Roehampton futures tournament, which was his second futures title in two weeks, both coming on different surfaces in different countries. Halys arguably has the best serve of anyone on this list and his only real weakness appears to be his movement. The reason he isn't higher on the list though is that there just isn't a lot of room for improvement. He certainly hasn't peaked yet, but he may peak much earlier than others on the list.

19. Duckhee Lee (KOR) Age: 17, Rank 228

Lee is by far the highest-ranked player of his age group with Tsitsipis in a distant second, which is exactly why Lee makes this list. However, his results lately have not been particularly encouraging as he tries to refine his game against players on the Challenger Tour. He has dominated the futures tour with 87 match wins and seven titles already, but on the Challenger Tour he is well below the .500 mark and rarely beats anyone ranked higher than him. He is only 17, so it is much too early to give up on Lee, but he has made the transition to the Challenger Tour look extremely difficult. Lee doesn't have much athleticism, but he is a very skilled player, which might be enough to do well in junior tennis and on the futures level, but it still hasn't let to success beyond that. Until then, Lee is just barely staying on this list.

20. Michael Mmoh (USA) Age 18, Rank 387

Picking the 20th player on this list was not easy and it changed between a lot of players. Ymer, Escobedo, Kozlov, Opelka, Paul, Jasika, De Minaur, Luz, Nishioka, Chung and Valkusz just to name a few. Ultimately, I went with Mmoh because of his style of play. The American (stop me if you've heard this sentence before) has a great serve and forehand, but leaves a lot to be desired on the backhand. He also has great athleticism and has also shown ability to perform both on hard and clay courts and even won a Grade 1 junior title on grass. As a junior, he reached the No. 2 ranking and won a Grade A title in Mexico, where he defeated Nathan Ponwith, Mate Valkusz, Andrey Rublev, and Seong Chan Hong.