Some here have argued Portis wouldn't play in Boston due to our depth, suggesting that our frontcourt depth is comparable to that of the Bulls. From a quantity standpoint, sure. Quality-wise, no way.
Others argue he benefits from being on a talented team where his mistakes are covered up. First, no doubt he's making rookie mistakes, but the good things he's doing far outshadow the blips right now. Second, if you believe he's benefiting from his teammates, you probably aren't watching him play. He makes nice plays in isolation (especially around the rim/in the post), shoots surprisingly well from behind the arc off P&R, and finishes in transition.
These abilities have little to do with who else in on the court; in contrast, we would be salivating for a guy that can score in the post, hit from 3 (without hesitation), rebound, and roam as an active defender with legit size. I'd argue it would be easier for him to score in our system, in fact, because he wouldn't have to deal with chuckers like Rose, Butler (42 pts tonight), Mirotic (endless green light), and take a back-seat behind Gasol.
Last, his usage has been high in his stretch of play this year. He's very aggressive offensively, which is boding very well for him on a team where he's fighting for PT and opportunity.
I wasn't high on Portis pre-draft. I assumed he would be our selection, and I was fine with that, but prematurely decided we weren't going to find anyone of significant value at 16. I was not at all happy with Rozier, though. It made no sense to me then, unless Ainge had already decided Smart was not a part of our future. It makes even less sense now, as Rozier seems incredibly hesitant on the court, unsure where he wants to go or what he wants to do (all stop-and-go), is undersized, and far too similar to others on the roster (esp given our crop of bigs).
Hopefully Ainge has a plan with the roster and Rozier proves me wrong. For those that want to designate Portis to Maine as a Celtic, though, I can assure you that's a silly presumption and encourage you to actually watch him play before making bold statements. Maybe that's just a pet-peeve of mine, and I'm guilty of dumb posts too... but the kid can flat out play.