Harrison I'm sure you have seen him enough by now.
Kudla- Very good baseliner, backhand is the stronger side and he has good movement. Really nice potential.
Sock- More raw as he has only been pro for a short time, but he has a very good serve and heavy attacking forehand. Good at the net, also. Needs to improve his backhand and movement.
Kosakowski- Only one of the group with a 1 handed backhand. Decent but nothing stands out.
Collarini- Haven't watched him too much but he's a left handed claycourter in the mold of so many other similar players.
GO Roger Federer, Nick Kyrgios, Borna Coric, Vasek Pospisil, Kei Nishikori, , Milos Raonic, Jerzy Janowicz, Grigor Dimitrov, Dennis Novikov and Bernard Tomic and Mikael Ymer
Thiem will be No 1 by Dec 2017
Nick Kyrgios will be No 1 by Sep 2018
Mikael Ymer will be No 3 by Dec 2018
Alexander Zverev will be No 3 by Dec 2017