Hart has only played 151 minutes with the Cavs, which equates to five games of 32 minutes, so it's still very early, but it's interesting to look at where he ranks compared to other bigs around the league. I used cleaningtheglass.com which ranks each player in various categories compared to others who play the same position.
In the on court/off court category, the Cavs are outscoring their opponents by 15.4 points per 100 possessions with Hartenstein on the floor. This ranks him in the 98th percentile among NBA bigs. Does that mean he's one of the top bigs in the league? No, but it means the Cavs do very well when he's on the court. However, we have to consider two confounding variables. One is the fact that he plays a lot of his minutes against the opponents' bench players since Hart usually comes off the bench. Two, the Delly factor.
The Cavs are outscoring opponents by 20.0 points with Delly on the floor, by far the highest on the team. Since Hartenstein and Delly usually come in together you have to wonder if Hart is just riding on the Delly train and how much he is personally responsible for that +15. If Hart were starting and Allen was coming off the bench would Allen be the one who is +15? ( Allen is -1.4, by the way).
That +15.4 is mostly offense; the Cavs are 14.2 points better offensively and 1.2 points better defensively with AH on the floor.
Breaking it down, AH is in the 73rd percentile in points per shot attempt. I think that's mostly because he doesn't force crazy shots (like JaVale McGee, who was in the 31st percentile). He only shoots when he has a high percentage look. HIs effective field goal percentage is in the 84th percentile.
AH is in the 76th percentile in shots at the rim and the 86th percentile in the short mid-range (4' to 14') area. He has a nice push shot from the middle of the lane that he gets off quickly and accurately. He is great at drawing fouls, ranking in the 88th percentile in getting fouled on the shot attempt.
One thing I like about AH and perhaps a reason his EFG% is so high is he understands when he doesn't have a good shot. For example, whenever Tristan Thompson grabbed an offensive rebound he would force it back up, even if he were surrounded. It's like he figured that since he worked so hard to get the ball he earned a shot and was going to take it. He used to get stripped or blocked on put-backs a lot, which negated the offensive rebound and frustrated the hell out of me.
Hartenstein grabs offensive rebounds and if he is in a crowd he'll frequently kick it out for a 3-point shot or a new play rather than trying to plow his way to the rim in a mass of bodies.
Passing is where he shines, ranking in the 97th percentile among bigs in assists per usage. Growing up in Europe with a father who made him play point guard as a kid is paying off. He's had a couple of games with seven assists in limited minutes. He's above average in offensive rebounding, ranking in the 65th percentile.
His problem on offense is turnovers where he is in the 14th percentile. Part of that is due to his confidence in his ability to thread the needle with his passes and his aggressiveness passing the ball into tight spaces. The upside is more assists; , the downside is more turnovers. But he has not played many NBA minutes and didn't play in college so as he gets more experience his judgement will improve and we'll see fewer turnovers on low percentage passes, I'm sure.
Defensively he has some huge strengths. He's in the 96th percentile among bigs in block percentage; Allen is in the 86th percentile. The Cavs are in great shape going forward in the area of rim protection. Hart is average in steal percentage.
He also excels on the defensive glass, ranking in the 96th percentile. But despite being a terrific shot blocker and defensive rebounder the Cavs are only 1.2 points better defensively when he's in the game.
Part of that is due to his propensity to commit fouls - he's in the 14th percentile. Again, I think this is due to being inexperienced and overaggressive. He needs to learn how to play solid defense with less contact. He needs to keep his hands back, move his feet better, and disrupt or block the shot using his length without fouling.
These numbers will change as we finish the season but I think they show a pretty good picture of where this kid is right now because the numbers match what we're seeing. He's excellent offensively with a high shooting percentage, outstanding passing for a big, and he's above average on the offensive glass. He just needs to reduce the turnovers and maybe develop a better low post game for when he's isolated against a guard or small forward after a switch.
Defensively he's just OK, but his shot blocking and rebounding is right at the top. I think he's a little slow reacting to the dribble penetration and the quicker wings and guards can blow by him for layups. He also fouls too much. I think it's a matter of him better understanding how much space to give smaller players and not to crowd them which results in blow-bys. Make them take a jump shot and then contest it using his length to hopefully hurry or alter the shot and force a miss.
As for him putting up big numbers against bench players, well, bench points count just as much as starters' points. If your starting five are all -2 to +2 while your bench are all +8 to +10, then you win. The Cavs have no superstars and they may not have any in the foreseeable future. Kawhi Leonard and guys like him are not coming here. So the approach may have to be putting together a starting unit that can just hold their own and winning the game off the bench with guys like Hartenstein, Nance, Wade, and Prince dominating the opponents' bench.