Alexandr Dolgopolov is one of those players that I try to see whenever I'm at a tournament. (Check out my encounter with him last year here.) His serve is a bit unorthodox, but he makes it work, and the combo is fun to watch. Unfortunately, he lacks consistency. One set he'll play incredible…the next, it's as though he's mentally checked out. As a spectator, it makes for some interesting viewing. I first started watching Dolgo in 2011 when the SDP Junior Editor noticed him and predicted he was a rising star. Sure enough, by 2013, he broke into the top 15 on the ATP tour. I'm not sure whether he's had some injuries, but his ranking has dropped into the 70s. He's still young and has lots of tennis to play -- and possibly have that big breakthrough, which I would be really excited to see.