I bet Rozier killed it and that's why Ainge reached for him at #16.
The story was that Rozier 'killed it' in one of their other tests. The Celtics run a drill that traps the ball handler in a particular way. Normally, the best players get out of it 3 out of 5 times. Apparently Rozier blew it up 5 out of 5.
Huh, is Rozier an elite ballhandler? I've never thought of him that way. If he is, I can see why Ainge took him... elite handles+burst is a pretty sweet combo of traits for a PG.
His handle is pretty weak, I assume he was able to use his crazy burst to avoid being really trapped.
Also, we never really had a chance to work out the Irvings and the Wall's of the world.