The 2016-17 Boston Celtics were never going to be a great (or even good) rebounding team. The departure of Jared Sullinger this past summer, a top-20 rebounder in the entire NBA last season, sealed that fate before the season even began.
The problem for president of basketball operations Danny Ainge is that the Celtics were a subpar defensive rebounding team even with Sullinger and fellow former teammate Evan Turner in the fold. Boston finished 26th in the league last year in defensive rebounding rate with that pair standing out as two of the team’s five best defensive rebounders.
Al Horford, an average defensive rebounder at age 30 by the metrics, was signed to replace Sullinger in the starting five, while no true replacement was ever brought in for Turner’s rebounding contributions on the wing. Those roster realities led to rebounding anxiety before the year even began for the man who put the team together.
“My biggest concern even before the year started was defensive rebounding,” Ainge explained to the Boston Herald. “I think that we are a small team and a quick team, and we have to do it collectively. We don’t have one of those guys that gets all the rebounds, and that was our problem last year, and it’s going to be a problem this year, too.”
Through seven games, a problem would be a healthy understatement to describe this team’s issues on the boards. The Celtics rank dead last in defensive rebound percentage (70.8 percent) and total rebound percentage (45.3 percent). That’s a four percentage point drop in both categories compared to last year.
Part of the trouble can be attributed to the recent injuries of Al Horford (concussion) and Jae Crowder (ankle) who have statistically been two of the team’s top rebounders to date. However, Isaiah Thomas refused to excuse the team’s pathetic effort on the glass.
“One thing I think is, we’re not the hardest-playing team no more,” Thomas told reporters in Washington Wednesday. “I think that’s what made us special, that’s what made us good, us playing harder than the other team. Being more scrappier, getting all the loose balls. Rebounds don’t come to us no more because we’re not playing hard.”
Stevens called the Celtics out for being a “finesse” team earlier in the week, and the early numbers bear that out. The question is whether the Celtics have the means to change that label with their current personnel and avoid situations like this:
The Wizards got an offensive rebound on this missed shot pic.twitter.com/Ho1F8R4jx9
— Adam Himmelsbach (@AdamHimmelsbach) November 10, 2016
“I think it’s a combination of factors,” Ainge said on Toucher and Rich of the rebounding issues. “Losing some of our best defenders is a problem. Again, our guys are not rebounding the ball. It’s not an emphasis. We’re not blocking out. We can do much better than we’re doing, even with the current players.”
A closer look at the individual numbers demonstrates that Ainge is right about expecting more from his team’s current personnel up front.
Defensive rebounding rate (career rate in parentheses)
Jae Crowder: 24.1% (14.0%)
Tyler Zeller: 18.8% (18.6%)
Al Horford: 18.8% (22.3%)
Avery Bradley: 18.2% (8.5%)
Kelly Olynyk: (17.2%)
Amir Johnson: 13.1% (18.7%)
Gerald Green: 12.2% (11.1%)
Marcus Smart: 11.5% (10.7%)
Jordan Mickey: 11.0% (12.2%)
Jonas Jerebko: 10.8% (17.3%)
Isaiah Thomas: 8.2% (7.8%)
Jaylen Brown: (7.5%)
A few key takeaways stand out from these percentages. First, Crowder (while healthy) and Bradley are doing more than their fair share of rebounding for their size, with dramatic increases from their career numbers on the glass. Asking them to keep up that kind of pace for an entire season would be far fetched.
Boston’s bigs (outside of Tyler Zeller) have also posted sharp decreases from their career numbers thus far, particularly with Johnson and Jerebko as the main offenders. A 6-foot-7 Jaylen Brown failing to grab a higher percentage of rebounds than 5-foot-8 Isaiah Thomas is a concerning trend too.
The biggest predicament from these numbers though is the fact that no one outside of Crowder ranks among the league’s best 110 defensive rebounders. Therefore, Ainge is essentially relying on a bunch of average and mostly below average defensive rebounders on a nightly basis. That’s a strategy he openly admits.
“We can win games and have won games by not being a great defensive rebounding team,” Ainge told Toucher and Rich on Friday. “If we just go put someone out there that can get defensive rebounds, then we’re going to sacrifice other things unless we get a complete player, like we have in Al and Jae.”
One thing that Ainge may have underestimated about that mindset is how crucial having a superb rebounding anchor like Sullinger is to being able to get away with it. Without him, the Celtics have been counting on the likes of Bradley to lead the team in rebounding (7.9 per game), cover the team’s best scoring guard, and score 15+ points per game.
That’s a lot of responsibility for a player and counting on smaller players to rebound every night has contributed to the slippage the Celtics have seen overall on the defensive end (Boston ranks 30th in defensive rating). Ainge has sacrificed defensive rebounding, but the team isn’t making up for it in any other facets of its defense with perimeter (3-point shooting) defense and turnovers forced both sharply down from last year.
Unlike Sullinger or Turner, starters such as Crowder, Bradley and Thomas have never been considered “elite” rebounders for their respective positions. Combine that reality with big men that have shown decline in their career rebounding averages as they approach age 30 (Horford, Jerebko, Johnson) and there is no clear cut internal solution for Ainge.
The Celtics’ bigs can and will be better on the rebounding front than what we’ve seen in the first seven games, but even with the proper level of effort and good health, Boston’s roster will be fighting for its life on the glass most nights this year.
“[Rebounding is] a huge area of emphasis because, like I’ve said before, we have to be a team that’s even on the glass to have a chance to win,” Brad Stevens explained. “And we have to work really hard to be even on the glass. It’s just who we are. So we’ve got to do it. We’ve got to be better. And this is something that you can control. And we just have to get better at it.”
Ultimately, the Celtics’ biggest flaw on the rebounding front might boil down to roster construction. Stevens can instruct his guys to increase the emphasis on the glass, but this is one area in which Ainge is probably going to have to add a piece (via free agency or trade) to truly address the problem.
All statistical information via Basketball-Reference.com unless otherwise noted.