Shouldn't the Cavs be Better at Defensive Rebounding?

Before the season, the Cleveland Cavaliers looked like a team that was going to be very strong on the glass. They were a top-10 team in rebounding rate in 2013-2014, and were replacing Tyler Zeller and Anthony Bennett with Kevin Love and LeBron James in their frontcourt rotation. The Cavs rebounding well seemed like a foregone conclusion.

On the offensive glass, this has definitely been the case. The Cavs are currently seventh in the league in offensive rebounding rate, grabbing 27.4 percent of available offensive rebounds. And while that hasn't led to a ton of second-chance points (They rank 17th in the league with 13 second-chance points per game), it has helped the Cavs prevent opponent fast breaks, where they allow just 11.7 fast break points per game - seventh best in the league. Timofey Mozgov is a top-20 offensive rebounder in the league, and Tristan Thompson has developed into a ridiculous offensive rebounder, trailing only Pistons center  Andre Drummond and Clippers center DeAndre Jordan in offensive rebounding rate 15.4 percent. Considering he gives up at least three inches and 25 pounds to both of those guys, that's incredible.

On the defensive rebounding end, however, it's been.......less than impressive. The Cavs rank 18th in the league in defensive rebounding rate, grabbing 74.2 percent of available rebounds on that end. They limit second-chance points well, but the big advantage that was assumed heading into the season hasn't been there for the Cavs. We expected the Cavs' rebounding to be a huge help to their defense and help the team initiate plenty of fast breaks. So far, neither of those things have happened, as the Cavs are in the middle of the pack on fast breaks and 18th in allowing offensive rebounds.

The Cavs' struggles to rebound consistently on the defensive end are strange and difficult to explain. As with most team strengths or weaknesses it's partially due to individual struggles and partial a team-wide issue.

I'm not here to pin this on Love, as might be the first thing many would think of when they see "CAVS STRUGGLE TO REBOUND." Love's been a bit of a concern on the offensive glass (7.4 ORB%, which is a problem when your career average is 11.7 percent), but he's actually still leading the Cavs in defensive rebounding rate. His 27.1 percent is lower than his career average of 29.4 percent, but it's still the best on the team, and his lower rate might be due to the presence of Mozgov, who's much, much, much better than Love's former frontcourt-mate Nikola Pekovic on the defensive boards. Love's one major flaw on the defensive glass is that he has struggled to grab contested boards this year, grabbing an uncharacteristic 38.7 percent of contested boards. That could be a function of him playing hurt throughout the year and not doing well with contact. Regardless, while he hasn't been dominant this year on that end, he's been good.

Tristan's seen a similar dip in productivity this year, dropping from a 21.5 DRB% last year to 18.5 this year. However, he's defending in space a lot more this season, and that's probably what accounts for it. Tristan's grabbing a healthy 49.1 percent on contested boards, and his per 36 numbers have increased with his slight minutes reduction. He's been okay.

The most significant dip comes from LeBron, who is down from a 18.9 DRB% to 14.8. LeBron's defending more on the perimeter with the Cavs than he did with the Heat, but that doesn't explain the complete drop in LeBron's rebounding numbers. His offensive rebounding numbers have remained pretty consistent this year, making things more confusing. He's struggled with injuries too, so that could be an explanation, especially for his laughable contested rebound rate of 23.5 percent. However, since he returned from his hiatus, James hasn't really improved there, still grabbing around 25.4 percent for his last 10 games, per SportVU data. Considering LeBron has been one of the better rebounding forwards throughout his career, it's been very disappointing to see his numbers not live up to his previous standard this year.

Scheme also likely has to do with this. It's no secret that the Cavs are letting opponents convert shots at the rim at a high percentage (57 percent) and volume (23 attempts at the rim per game, per SportVU). Because of this, and their aversion to fouling, the Cavs' bigs really aren't consistently in position to grab rebounds from shots inside, save for Mozgov, the team's lone rim protector. The Cavs are grabbing 41 percent of their rebounds off shots from outside, which are less likely to be contested, but also come less frequently than missed shots inside. It's hard to determine exactly what effect the Cavs' defensive scheme is having on their rebounding, but it could be a factor.

One final nugget that's far too weird not to mention: Matthew Dellavedova leads the team in rebounding differential. Dellavedova isn't a good rebounder by any means; he has a rebounding rate of 5.2 percent and a defensive rebounding rate of 7.2 percent. However, the Cavs have a significant improvement in their defensive rebounding when he's on the floor. With Delly, the Cavs post a DRB% of 76.7, which of course is the highest mark of any Cavs' regular. With him off, their DRB% dips to 73.2, meaning the Cavs have a 3.5 percent advantage. Compare that to the Cavs bigs; Mozgov only creates a 0.6 percent increase when he's on the floor, the Cavs have a slight decrease in DRB% when Love is on the floor (0.3 percent decrease), and they are worse by 1.4 percent when Thompson is out there. I have no idea what this means, except that Delly just has no regard for numbers that make sense.

The Cavs have gotten good production from Mozgov since they traded for him, but LeBron, Love, Thompson and even pre-injury Anderson Varejao all have rebounded worse than their previous standard this year. That's quite frustrating, considering the argument for the Cavs being an elite rebounding team was based on the production those guys had put forth previously. Defensive rebounding up to their potential could still help the Cavs' defense create extra stops and fast break opportunities, which have both been disappointing so far.