What about the Sixers defense?

Last season, the Sixers ranked 18th in the NBA in defensive efficiency with a mark of 107.73. No real surprise that the Sixers weren't a great (or even good) defensive team last year, but I was a little surprised to see how they reached that ranking.

Most surprisingly, the Sixers were actually ranked 4th in opponent's turnover rate (DTOR). Despite forcing a high number of turnovers, the Sixers were a slightly below average defensive team because of their average defensive true shooting percentage (TS% = 16) and piss poor defensive rebound rate (DRR = 27). What explains this wide range of ability on our three major defensive statistics? Living in Boston, I didn't have many opportunities to see the Sixers play last year (to put it charitably, they weren't on national TV many times), so I can't really make an evaluation with a high degree of certainty. However, my best guess is that the Sixers defensive story begins and ends with Samuel Dalembert.

If you recall my post from yesterday, you probably remember that having mobile big men seems to play a big role in whether or not a team forces a number of turnovers. Dalembert is, if nothing else, extremely mobile for a big man. The top defensive teams that force a high number of turnovers are able to do so because their big men are mobile enough to help force the turnovers and to still recover quickly enough to be in a good position to help out defensively. If I remember correctly, one of the reasons Coach Jim O'Brien and Samuel Dalembert didn't get along well during O'Brien's stint with the Sixers was because O'Brien thought Dalembert was slow on his help defense rotations. These defensive numbers indicate to me that Dalembert is still slow on his rotations--he's mobile enough to help force turnovers and recover, but he doesn't read the game quickly enough to actually recover effectively. He still gets his blocks because of his athleticism, but he doesn't get enough of them to make up for his late rotations (thus the average DTS%) and his late rotations put everyone out of position for getting rebounds (thus the putrid DRR).

This story sounds believable to me, but like I said, I didn't actually get a chance to watch many Sixers games this past year. I'm being hard on Dalembert, but maybe that's being unfair to him. I tried to look at +/- stats from 82games.com to see if they shed any further light on the subject, but they weren't particularly helpful. The Sixers were worse with Dalembert not on the floor, but mostly that was because the offense was much worse when he was not playing (the defense was also worse, but the difference wasn't nearly as big). Assuming my intuition is correct, playing Dalembert might be the Sixers best option defensively (and looking at their roster this isn't hard to believe), but that option doesn't seem likely to lead to very good results unless something changes dramatically. In watching the Sixers play this year, we'll just need to make sure and pay special attention to the big man rotations on the defensive end of the court to see what is really going on.