Nets by the numbers: The Brook Lopez effect... on defense?

Brook Lopez catches a lot of flak for not fitting everyone's cookie cutter mold of what a center should be; he is not a double digit rebounder, he plays a lot on the perimter, he is often used as a screen setter on the perimeter, he doesn't block 2 shots a game, and he has a reputation as one of the worst defenders around. John Hollinger even said Okur is an upgrade defensively from Brook Lopez. Here, I will attempt to show how losing Brook Lopez has turned the Nets from a slightly below-average but passable defense into the worst defense in the league. More after the jump.

I will grant the caveat that the sample sizes are not nearly equivalent. It's been 14 games vs. 82 games last year. The Nets have the potential to improve defensively. That being said...

First, the basic raw numbers:

In 2010, the Nets gave up 100.4 points per game (ranking 15th in the L), 46.5 FG% (19th), and a 36.4 3P% (19th). Rather average to below average numbers. This season thus far, the Nets are giving up 100.7 PPG, a 49.1 FG%, and 44.2 3P%. The PPG allowed ranks 3rd worst in the NBA, and the FG percentages are the worst (and not by an insignificant margin).

If you want to look at rate stats, the Nets are far below 2010 level. Our defensive efficiency (points per 100 possessions) is 109.7, worst in the league by almost 3 points. Opponent TS% is 57.1%, worst in the league. Last season it was a 107.0 defensive efficiency and a 54.7 TS%, which ranked 22nd and 19th respectively. By almost all statistical measures, the defense has been the worst in basketball. The personnel hasn't changed much, outside of getting rid of Outlaw (who most consider a bad defender) and Lopez's injury (also considered a horrible defender).

How does this prove Lopez has any effect, you ask? Does he effect 3P%? I would argue that having a guy who can protect the rim does help defending the 3. Is Lopez an effective rim defender? I would argue that last year, he was. The Nets ranked 7th in the league in at-rim FG% with 61.6%. This season, they are 6th worst, at 66%. The Nets are giving up an extra basket at the rim per game over last year despite allowing .2 less attempts at the rim per game. I know Brook doesn't play all the minutes, but you have to think his length is a big reason why the Nets have a pretty stark difference between last year and this year. True, Lopez isn't much in man post defense where he can get bodied by bigger centers and it's reflected by the Nets ranking 3rd worst in FG% from 3-9 feet (roughly at the same percentage they are at now), but he helped the Nets do the job in stopping dunks and layups, which is the category where you see the majority of shot attempts.

What about rebounding? Lopez averaged a mere 5.9 boards per game. Absolutely horrendous for a 7 foot center to grab less than 6 boards a game. But how are the Nets rebounding without Big Brook? Granted, they didn't replace Brook with any great bodies on the boards, but they shouldn't make the team any worse at clearing away boards, right? Well, not right. Lopez did some solid work boxing out. How many times did you see Humphries sky in unbodied for the rebound? It was almost Jayson Williams-esque. Jay, especially on the offensive end, used to zig-zag and spin and run like Reggie Bush towards the basket so he can grab the rebound uncontested. Not to say Jayson couldn't body up on people (or body them...) but this was a more effective rebounding method (if you have the conditioning for it). Hump did a lot of this without the zigging... he often had free runs to the basket for boards. A lot of this was because Lopez was content to step back and let Kris clear away boards. The Nets ranked 14th in the league in defensive rebound rate in 2010, grabbing 74.19% of available defensive rebounds. A fair ranking considering you have a center that grabbed 5.9 per, to be in the top half of the league in clearing away the defensive boards. This year, without Lopez? 70.15%. That figure is 3rd worst in the league. NJ was 17th in boards per game last season and was a -1 in rebound differential... this season they are 2nd to last and have a -2.8 differential. No one will ever confuse Lopez for a dominator on the glass, but with him the Nets were an average rebounding team despite a PG, SG, and SF that don't really rebound their position well (though Deron did for the 12 games he was there). This year they stink despite having their main rebound cog from last year (The Hump), and a SG in Brooks who rebounds his position very well.

None of this is to say that Brook is a great rebounder or a great defender. He's not. But when you are getting down on his ability when you see 5.9 RPG or think that he's an absolute liability defensively, look at the bigger picture and you'll see that he's likely middle of the road, and that's decent for a guy with Brook's offensive talents. Thoughts?

All this is according to hoopdata.com