No. 15: Stefanos Tsitsipas
What a year for Tsitsipas. He was ranked No. 131 during the fall of 2017. He ended up 2018 ranked No. 15. For the 20-year-old, he rose way up and he was upbeat. Even during the fall, he changed a dramatic amount. For him, he was mentally smart, more aggressive and stronger. The Greek Tsitsipas reached the ATP 1000 Canada, upending Dominic Thiem, Novak Djokovic, Alexandra Zverev and Kevin Anderson before losing to Rafa Nadal. He won Stockholm, and he grabbed the Next Gen ATP Final. He may be a little bit erratic, but as long has he continues to get better, he will push in the top-10, and maybe even further. 
  
No. 14: Kyle Edmund
When he is erratic, the Brit showed that he is worried. But now, Edmund, who finally appears to believe in himself. Without a doubt, he can be confused on court, and he needs to be better with his returns. When moves forward, his returns improve substantially. In the Australian Open, he reached the semis, beating Grigor Dimitrov before he lost to the huge serving Marin Cilic. During much of the year, he was spotty. In the fall he kept working off court and on court, and he won Antwerp in October. Look, Edmund has to go into the net and put it away — more frequently. He still has a lot of work ahead, but if he does, in 2019, he can even reach the final at a Slam or in the ATP 1000. He will move up, that is for sure.  

No. 13: Fabio Fognini
During the last two years, the Italian has been so much more consistent and he is calmer than he used to be. He can smack the forehand and backhand, he is very quick and intelligent. For sure, he can still become angry, and extremely frustrated, and his brain blows up. However, when he begins to breathe, and look at everything, then he can become very intelligent and he can hit so many cool shots. Fognini won three events this year: Sao Paulo, Bastad (on clay) and Los Cabos, on hard court. That shows consistency. However, he has yet to reach to the finals at the Grand Slams and the ATP 1000s. Clearly, he wants to do that for the first time. He is 31-years-old, and he has a few years left, but in 2019, he needs to lock it in and stay there.

No. 12: Borna Coric
A year ago, I wasn’t sure that Coric could focus enough to succeed. In 2018, he played substantially better, he began to grow up, and on court, he decided that he would grind until the sunshine went down. And that’s he did, playing many long rallies — super, long rallies — and when he had an opportunity, he would strike, instead of just hitting the ball back. He won Halle. In October, he reached the ATP 1000 Shanghai in the final, upending Stan Wawrinka, Juan Martin del Potro and Roger Federer, before he losing to No. 1 Novak Djokovic. That was his best week, ever. Next year, he will push really hard to reach the top 5. He is ready, but can he go very deep at the Slams? That will be an investigation.
 
No. 11: Karen Khachanov
The tall Russian had a terrific fall. He captured the Paris Masters, shocking four top 10-ers: John Isner, Zverev, Thiem and Djokovic. The 22-year-old also won Moscow and Marseille. At the US Open, while he lost against Rafa Nadal, it was very close. He is a huge hitter on both sides, and his serve is massive. But, like the younger players, he does not return very well. Khachanov has to continue to work on his returns; I mean for hours and hours because the Grand Slams winners — like Federer, Djokovic, Nadal, Andy Murray and Wawrinka — they return consistently and deep. Other Russians – Marat Safin and Yevgeny Kafelnikov who won a couple of majors – could jump on the first and second serves. Not only where they capable of putting it away at the net, but were devastating with their return game. The young 6-foot-6 Kachanov is taller and hits harder than both of them. As he as said, he works off court all the time. So in 2019, if is he continues to revamp, he will be there deep in many semis and the finals. He is that good.