I like to think I know a lot about basketball. I love football, but I didn't play it so I watch it like I think most people watch basketball, they follow the ball and only see the end where KO's man is scoring.
I watch basketball like someone who played it for 6-8 hours a day through high school and when I wasn't playing it, I was watching it. And when I wasn't watching it I was watching coaching instructional tapes of it.
KO's biggest problem defensively is that he tries to help too much. Sometimes you have to just let your teammate try to defend his man on his own. Smart did this last night against Utah and got burnt. Usually Smart is incredible at help defense and getting back to his man but KO can't do what Smart can as a smaller guy. But maybe this is the way he is being coached. Maybe Steven's philosophy is help and make them make the pass and open shot.
I can say though, if you just watch KO on defense he is a high BBIQ guy. He constantly sags off his guy to guard cutters, opens the door for guards on picks, helps out from the weak side more than Bass or Sully for sure, and gives great effort even though he lacks some things athletically. He is terrible at blocking out. Now he blocks out almost every time and is incredibly physical doing it which he has started getting away with, but it is that face guarding blocking out that doesn't let him get the rebounds. He has to learn to block out with his rump. Maybe it is because he gets pushed around from behind and he needs some bulk and to get stronger but his face guarding just means someone else has to get the ball, even if it comes right to him.
Offensively, I don't think I've ever seen a player not want to shoot more, who was actually good at it. He can't get in a rhythm because he shoots so seldom. This is OK if we have some chuckers, and hey we do. So his good passing, moving the ball from side to side, and willingness to set good tough picks is what I think make his +/- good.