Let's put him somewhere between Dirk and Larry, and call it a day! LOL
I don't expect KO to be any of the above. He's going to be his own guy. But the skillset he has at 7 foot is rare and he also couples that with a very high basketball iq, motor, and work ethic. To me that spells success.
Aside from his t-rex arms and lack of elite athleticism, he has EVERYTHING ELSE going for him. I see Kelly as the kind of guy who will work hard and quietly improve his game from year to year until he is a fairly complete player.
He will never be an 'elite' defender, but can he become serviceable to average with enough work, I don't see why not. Can he leverage his offensive skillset and basketball IQ to be a very dangerous scoring/stretch big man? Yes he can.
I can easily see a rookie year of 12/5, a second year of 15/6, and a third year at 18/7. All while dishing out 2-4 assists per game. That's a valuable offensive player to have and all that in a 7 foot package.
Do we still need a 'real center' to compliment him? Sure. But Kelly Olynyk can be a positive part of the puzzle for the Celtics.