I guess if you really wanted to know you could look at family history. I grew about 2 inches between age 19 and age 21 but that's fairly rare and a lot of people in my family had late growth spurts. As a primary ballhandler I don't know that an inch more will change his outlook much though.
This is the point I would make as well. Luka is still a teenager -- he just turned 19 -- and he was the MVP of the Euroleague. There was
an interview with ESPN earlier this year which made reference to him grabbing Snickers bars from the gas station and name dropping Five Guys (a particularly greasy but tasty hamburger chain). If he's this good right now when he
spends his free time playing video games and snacks on candy bars and fast food burgers and fries, how much better could he be with a professional training staff and a nutritionist at his disposal? He's got more natural talent than he knows what to do with. He might not ever be an elite run and jump athlete but it looks like he's got quite a bit of room for improvement just by working on his body. There is sometimes a fear with somebody so brilliantly talented that they won't want to work hard because everything has always come easy to them. But if that's where we're at when looking for weaknesses, I think that's pretty telling of just how special he is. He's clearly the best player in the draft to me. I'm a big DeAndre Ayton fan but I'm hoping Phoenix picks him anyway and I'll be very upset if we decide to pass on Luka for some reason.