Anyone think that perhaps it is because he is starting?
I don't think that.
When JR first came to the Knicks from Denver, he was playing very much like you see now. He was even considered a Shumpert type defender in addition to his obvious offensive skills.
When he won 6th man of the year, the team had Jason Kidd and was very good. Again, he played like you see now.
A lot of things happened after that. The team got rid of their veteran leaders (Kidd etc) and went downhill. JR actually had some knee surgery as well, although not catastrophic. As he has stated, living in NYC (also his hometown) didn't help. He kind of lost interest the worse the team got. But look around the NBA, it's hard to keep motivated when your team stinks - however JR is not the strongest person on the block either.
I guess what I am saying is that he has had that ability all along. Still a very good athlete and still not that old. It just got buried in a dysfunctional situation - both team and personal.
I will say this (and I did see him a lot on the Knicks living in New York state) he has reigned in his shot selection quite a bit AND has focused on defense. He has matured. His quick hands on the Cavs adds to a number of guys with that quality here.
Announcers say he is easily influenced by teammates and that seems to be true. When he had strong leaders on those Knicks teams he thrived. Same here now.
Seriously, adding a guy with his shooting ability to a team that already had Lebron, Love and Kyrie distracting defenses is almost criminal. And he has added athleticism, passing ability, and defense as well.
A total steal of a trade.