I have been believing for years that Nikoloz Basilashvili had the potential to reach top 20 one day. He is almost there now. I have watched him practice many times, and he is one of the hardest laborers in our sport. His technique is sound and he can play an all-around game.
Despite being physically built like a rock, he does tend to be half a step slow in direction changes, but in my opinion, he has compensated for that over the years by playing a progressively more aggressive brand of baseline tennis that allows him to remain in the dominant role during rallies.
Assuming injuries remain far away from him during the 2019 season, I do not see why he could not finally break into the top 15. I am guessing that his increased confidence, originating from the belief that he can now take out top players, will propel him to a strong start to next year.
To consider: Hopefully, he will not experience a letdown during the latter part of the season and carry the confidence into the preseason break. The most productive practice sessions take place when you believe in your game, ride high in confidence, and can fully focus on improving the granular details of your game.