I think the salary cap is expected to make a large jump next summer - so no, I do not see a situation where Sully is worth the max under the higher cap.
Main concerns about Sully even if he does put up 17/10 are:
(1) How good his conditioning and physical shape is (throughout the year)
(2) How good his defense is -- it was lousy this past season. That cannot continue.
(3) How efficient his scoring is -- only 50% TS% past two seasons.
How well he does in those areas are main factors in determining whether he'll earn (a) starter-money (b) quasi-star money (c) genuine star money.
(1) Agreed.
(2) Was quite disappointed with the defensive effort he showcased last season. The activity he showed after his injury late in the season and playoffs give me some promise that he might return to form. His rookie year his defense was a disaster, then in December or so he turned the corner, particularly with his defensive rotations and became a very dependable defender for us... more importantly when KG was on the bench. Want to see a return to that, and I thought I saw some of that in the playoffs.
(3) I think his TS% is more of an effect of his shot selection than anything else, and maybe even some because of coach's directives. I'm a big believer that the 3-point shot will be a huge weapon for him, sadly it hasn't paid dividends yet. We'll see.
But he can score the ball from just about anywhere in the floor, and if he was tasked with shooting from the elbow area to just inside the 3-point arc I think we'd see a spike in the TS% because he's VERY good from those areas. It's his most under-appreciated and least used weapon. His TS% in the playoffs was 60% though, so some more of that would be nice to see.
One area that he needs to improve though is his free-throw shooting, I think he should be much better from the line.
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In the end, though I'm not talking about MAX right now, his staying power will be highly dependent on what we do with our cap space this year, and what opportunities we find ourselves with in 2016.
That said, I wouldn't be surprised by Ainge taking a risk on a rookie contract extension before the season is over and hedge that he'll get good value on it, at the same time Ainge will probably prefer to go into the offseason with some level of flexibility to go after the big guys in free-agency, as much as those opportunities seem a bit far fetched to me (the good ones)... and the guys that may be actually available to us will be either a combination of "non-interest" to me and "overpaid as heck" once every single team in the NBA will be throwing money around.
Honestly, depending on how Sullinger looks during the Summer and how he arrives at camp and how salary cap situation looks going into 2016, a rookie contract extension would be of interest to me personally as I'm a fan of Sullinger, and he's still very young to boot so that's good. But I'll hold off on committing on this for the time being until I have a better understanding on how our cap will be looking after the moves this Summer and how Sullinger is looking physically.