There's nothing to explain. He ran in a two-man iso system where he wasn't a significant option. The Celtics run a ball-movement game. The differences are obvious.
I would remind you, as an example, that Ray Allen had a reputation as a poor defender when the Celtics acquired him. How's that working out now?
Personally, I never expect a 3 to rebound like a 5. Ever. Never had one in 20 years coaching HS and small college. Don't know anyone who has. And so you can get ready, Green's not going to get 37 minutes a game in Boston.
Different systems, different points of emphasis, different results. The key in evaluating a player isn't some idiotic number; it's footwork. Are his feet quick enough to get the results you'll have to have defending on-ball? Attitude? Will the player work as hard as you're going to want him to on the glass? Ball judgment. How does he react in transition? Intelligence? Can he grasp a fairly complicated defensive scheme in Boston?
Given Ainge's track record - with a few notable exceptions - I'm assuming he's already answered these questions. I know what my answers are to those questions, having seen OKC in person seven times this season, and another 25 times or so since I can't get them off my TV.
Getting Jeff Green for damaged goods is too good to be true, in my view.
I'm sure Green will be fine on defense.
However, I still want to know:
Why does Green have a bad shooting PERCENTAGE? I understand why a 2 man iso system would yield fewer shots for Green. But Why would any system cause him to convert a bad number of those shots? If he can't hit his open shots when someone in OKC passes to him, why will he hit them here? Hope he does, though.