Kingster
Hall of Famer
You're missing a couple of things that have to improve: 1) he's not very strong, surprisingly, for that body. Despite being 6'11" it doesn't seem he can bang with big centers. 2) his defensive awareness is very shaky; 3) he does not look very long out there -- limits a shotblocker; and 4) his timing is not great.
He's really quite bad defensively right now. I do agree that there is no reason for him to be this bad -- he's big enough and athletic enoguh and seemingly willing enough that he should at least be able to become an impediment, especially if he can bulk up and stop all of the silly bouncing aorund for fouls stuff. But as I've mentioned many times before, especially at Jason's age guys who are going to be actual intimiators are normally already intimidating. He may simply lack the instincts and length to be more than solid in there.
Well, Thompson isn't a center. He's a power forward, so I'm not troubled that he doesn't have the strength to battle the big centers. I look at his frame and I just don't see him having a problem with the strength of power forwards down the line. Yes, he doesn't have the explosive jumping ability to be a great shot blocker. However, I give more weight to lateral footspeed than shot blocking when it comes to defense, and he definitely has that. Defensive awareness is something that requires experience. You've got to give him another couple of years to start to get it. Then he can exploit that lateral quickness and his length to maximum advantage.