Rebounding is supposed to matter in the NBA. Old-timey wisdom says that controlling the boards is a central tenet to basketball success, right there alongside classics like "wanting it more" and "giving it your all."
It can be dangerous to accept broad truisms like those without really thinking about whether they make logical sense. But in this particular case—anecdotally, at least—it's easy to see how an emphasis on rebounding would have a positive impact on win probability.
After all, if you're controlling the glass, you're imposing your will, winning the all-important battle in the trenches and hustling. Perhaps more importantly, making rebounding a priority limits your opponents' second chances while maximizing your own.
All good things, right?
Here's the problem, though: The numbers we're seeing this year don't indicate a very strong link between rebounding and overall team success.
Per NBA.com, the Oklahoma City Thunder, Houston Rockets, Portland Trail Blazers and Indiana Pacers are all among the league's top six in rebound rate. If we stopped there, the connection between good rebounding and a good record would seem pretty strong.
But the Chicago Bulls, Toronto Raptors, Memphis Grizzlies and Detroit Pistons, all of whom are below .500 on the season, also check in among the top 10.
Looking at the bottom of the rebound rankings, we see that the Milwaukee Bucks, the NBA's worst team as measured by per-game point differential, also rank dead last in rebound rate.
Finally! That has to be the example that proves rebounding is necessary to win games. The Bucks get murdered on the boards every night, and they've got the fewest wins in the league. That settles it, right?
Exceptions to the Rule
Right behind those putrid Bucks are the Miami Heat, back-to-back champs who don't seem remotely concerned with securing missed shots. LeBron James' team ranks 29th in the NBA in rebound rate, and although the Heat present the most striking combination of impotence on the glass and dominance in the standings, they're not the only such example.
The Dallas Mavericks and Atlanta Hawks, both currently part of their respective conference's playoff pictures, are also among the 10 worst rebounding teams in the NBA.
Maybe the old-school principle that rebounding leads to success is a little outdated. At the very least, it's an imperfect theory.
Based on what we've seen so far this year, there are only a few things we can confidently say about the rebounds-to-wins relationship. First, it doesn't appear that good rebounding guarantees success. At the same time, bad rebounding certainly doesn't ensure failure; the Heat prove that rather demonstratively.
But if we take the 10 worst rebounding teams in the league, just three (the aforementioned trio of the Heat, Hawks and Mavs) have won more games than they've lost. So, at the risk of being a little too guarded, we can cautiously say that bad rebounding is more likely to lead to losses than good rebounding is to wins.
It's early, though. We're dealing with a sample size of barely more than one quarter of one season, which means drawing conclusions about trends—any trends, really—is a dangerous exercise.
Maybe if we isolate the Heat in an effort to figure out how such a good team has had such success despite devaluing rebounds, we'll get closer to a more satisfying answer.
The Miami Situation
First of all, Miami's overall rebounding numbers are naturally low because of how it plays. The Heat have the highest field-goal percentage in the league, which means their games necessarily feature fewer rebound chances, especially at the offensive end. Made shots don't yield boards.
In addition, the Heat are one of the league's best mistake-inducers. Their brand of trap-heavy, deliberately chaotic defense generates a ton of opponents' turnovers, which also reduces the number of rebounding opportunities in their games.
But those stylistic realities only affect counting numbers, and we've been talking about rebounds in terms of "rate," which means percentages are all that matter. In other words, Miami's style on both ends doesn't necessarily explain why it corrals such a low percentage of available rebounds.
The truth is Miami's poor rebounding numbers are the result of a conscious decision.
Playing small so frequently would certainly seem to be a factor, as would the Heat's tendency to leak out in transition instead of sending multiple bodies to the boards.
You get the sense that the Heat could rebound better if they wanted to. After all, in James' first year in South Beach, the Heat were third in the NBA in rebound rate, per NBA.com.
Knowing that, it seems like the Heat's failure to rebound is a choice—a choice that indicates Miami has found something it values more than securing missed shots.
Per Joseph Goodman of the Miami Herald, Heat head coach Erik Spoelstra doesn't shy away from his team's identity: "We do not have a double-digit rebounder every single night. That doesn’t make it bad or wrong. That makes us who we are."
Looking back at a couple of recently successful teams, Miami's stylistic decision isn't all that surprising.
History's (Very) Recent Example
Back in 2012, then-ESPN analytics guru John Hollinger noted how the 2011-12 Boston Celtics posted the worst offensive rebounding rate in NBA history. Overall, the C's pulled down just 47.3 percent of available boards, good enough for 28th in the league that season. The 19.7 percent of offensive boards they secured set a new low bar in NBA history, though.
Despite that glaring statistical deficiency, those Celtics gave the soon-to-be-crowned Heat a pretty good run in the Eastern Conference Finals. Terrible rebounding didn't prevent the Celtics from winning a lot of games. Maybe Miami saw something it liked in the way the Celtics played.
We're getting ahead of ourselves, though. It's too early to wonder whether the Heat formed their current style by copying a page from Boston's book. What's more important is the way the Celtics' rebounding informed spectators about the team's priorities.
Boston wanted to defend, and for a team that old and that slow, it was critical to limit opponents' transition chances. So the C's gave up on the offensive glass and made sure to get back. Based on their personnel, the Celtics made a conscious decision to ignore the well-understood benefits of offensive rebounding.
Those benefits are intuitive, and we've touched on the biggest one already: getting after your own misses leads to more high-percentage chances at close range.
Not only that, but this year's Portland Trail Blazers are showing that offensive rebounds also lead to a ton of wide-open three-point shots. Watch Robin Lopez haul in a miss and note how frequently the Blazers create terrific long-range looks as defenders scramble to recover from the paint out to the arc.
For the Celtics, extra offensive chances weren't worth it. They wanted to stop transition attacks on the other end.
A Logical Flaw?
But Wages of Wins' David Berri concluded in 2012 that crashing the offensive glass might not be as big of a hindrance to good defense as many people thought. I'll spare you the math, but here's his conclusion:
In other words, offensive rebounds are on the list of things to do if you wish to win.
Let me close by noting that offensive rebounds are not the only item on the list. And a team could win without being particularly good at grabbing offensive rebounds. For example, teams that shoot efficiently don’t have to worry as much about grabbing offensive rebounds because the ball is going in the basket.
That being said, it doesn’t appear that teams are hurt defensively by grabbing offensive rebounds. So if those rebounds are available, it seems like a good idea to have someone on your team grab these.
One of the best pieces of evidence in support of Berri's thinking is the 2011-12 Chicago Bulls. That team led the league in both offensive rebound rate and defensive rating, per NBA.com. Berri's conclusion suggests that offensive boards and good defense aren't mutually exclusive. The Bulls specifically proved that theory.
So much for conventional wisdom.
Rebounding Matters; Some Things Matter More
Ultimately, rebounding does matter in the NBA.
Teams that want to win should chase offensive boards. And they should certainly do their best to corral rebounds on the defensive end as well.
But NBA games aren't played in a vacuum. Every squad has different personnel that dictates which style makes the most sense. In the Heat's case, it's clear that at some point between the 2010-11 and 2011-12 seasons, they decided that some things were more likely to help them win than rebounding.
Creating havoc on defense, sparking as many fast breaks as possible and playing small made sense for Miami. To do those things better, the Heat sacrificed the floor balance that leads to good defensive rebounding and gave up the conventional big men that would lead to more offensive boards.
I don't think anyone is going to argue with the wisdom of their priorities.
It's worth noting that the Oklahoma City Thunder, Miami's Western Conference doppelganger, rebound very well. So, even between teams with many stylistic similarities, the prioritization of rebounding can vary.
Rebounding is important in the NBA. But like many other time-honored basketball truisms, the proposition that it's a prerequisite to winning isn't uniformly true. Based on the available data and the trends that have developed over the past few seasons, it's really more accurate to posit the following: Rebounding matters, but for some teams, other things matter more.