I'm not hating on Semi, or hoping he fails. I want him to succeed and help the Celtics. I'm just not as high on him as you are. I'm not particularly interested in combine results or college stats anymore, those are useful when you are attempting to guess how a draft prospect might work out, but now that he is in the NBA I don't think those things are relevant anymore.
Your point about combine/college (and I would even add Summer League) has something, but they're not irrelevant. What a guy can do is not only a function of his competition - it's also a function of his skills, and those are visible in his previous work.
So far his defense has been okay, not elite, not great, okay.
Brad Stevens was the one who said "elite". There's something that many fans don't seem to get yet:
They're using him as a stopper, putting him on some of the toughest covers in the NBA. His offensive has been horrible, not just bad shooting, but poor passing, no handle, and not in the flow of the offense.
"poor passing" - I can't tell where you might have gotten this. His turnovers are very low (10.1%, as a rookie!) and in particular he's had a grand total of
three bad pass turnovers for the entire season, in 455 minutes of play. Perhaps you've seen him make a mistake passing, but you're better off doing the hard work of looking at a lot of minutes, not just go on an impression. You have to rewind!
"no handle" - the short answer reaction is 'how the hell could you even know?' - since mostly his job is to spot up and shoot if he's open, rotate the ball if he's not. But there have been some intriguing moments where he shows some really skillful stuff: the baseline drives right under the backboard in the Lakers game where he gets the ball up high on the reverse - an unblockable shot; or the open-floor drive in the Phoenix game where he switches hands and eurosteps for a layup.
My favorite so far has no razzle at all, but it's the stuff coaches love: Thaddeus Young closing out on him at the arc, he upfakes, fakes the drive left to get his man off balance, and then takes a couple of dribbles right to beat him. Sabonis rotates to take away the baseline, leaving Theis open at the elbow. Semi delivers the simple pass and Theis knocks it down. That's at 5:12 of the fourth in the Indiana game (notice that he's in the game at crunch time there), if you want to look it up.
"not in the flow of the offense" - that's not what I see, at all. He doesn't force anything, shoots when he's open, doesn't freelance. Here's a couple of telling stats: his usage rate is an absurdly low 9.6%. That's the lowest on the team. His 3-pt attempt rate is .790, which is the highest on the team (unless you count Kadeem Allen), and an absurdly
high number, almost all spot-ups. 17 twos. Those stats tell you that he is doing
almost nothing at all outside of the flow of the offense. I hope that I am not impolite, but I find your assertion baffling, and the opposite of the obvious reality.
As of right now, I think his most likely ceiling is useful defensive specialist off the bench.
That's what he is now, already. But even saying that underestimates his role.
They're using him as a stopper, putting him on some of the toughest covers in the NBA. Are you predicting that he's already reached his ceiling? That's not likely.
He's not going to take mpg from Hayward, Brown, Tatum or even Morris. As of right now I would put him 10th on the depth chart (Irving, Horford, Tatum, Brown, Smart, Morris, Baynes, Rozier, Theis, Semi), when Hayward comes back he will be 11th.
He's ninth in minutes right now, in front of Theis, so your math is likely off by at least one slot.
The return of Morris did not affect his minutes, though the re-exit of Morris seems to have increased them. It's a fluid situation, it's a long season, ups and downs are inevitable. Would he have gotten floor time if Hayward hadn't been injured, and Morris were healthy? I'd bet not. But now he's earned floor time going forward. Brad's remark that he was "kicking himself" for not putting him on Devin Booker sooner is telling: this guy has a future.