NBA offensive rebounding fell for 35 years and has come back over the last 5. I don't know why either happened.
I get frustrated that scientific and medical papers so rarely report negative results (do not get me started about computer science), so here's mine. Offensive rebounding fell for 35 years and has climbed for the last 5, I ran the tests I could think of, and I still can't tell you why. The obvious culprit is the three-point shift, since missed threes are harder to get back. It isn't that: of the 9-point drop in the share of misses the offense recovers, the shift to threes is worth about half a point. The rest is teams recovering every kind of miss less well, twos included.
Per team per game (rebounds and missed shots, every season):
| Season | Offensive rebounds | Defensive rebounds | Missed shots |
|---|---|---|---|
| 83-84 | 14.2 | 28.8 | 45.0 |
| 20-21 (the low) | 9.8 | 34.5 | 47.2 |
| 25-26 | 11.4 | 32.4 | 47.1 |
The percentage of rebounds that are offensive starts at about 33%, drops to 22% in 20-21, and then weirdly goes up in the last 5 years to almost 26%. (offensive rebound rate by season)
It isn't that there are fewer misses to grab. Teams take about the same number of shots they took in 83-84 and make fewer of them, so there are more misses on the floor now, about 47 a game per team instead of 45. True shooting and eFG are both up, but a three that goes in is worth 50% more and a three that misses is just a miss, so neither of those matters to rebounding. (shots taken, made and missed)
I don't know why it dropped. But it did. Anybody have an explanation, and ideally data behind it?
Possible reasons without data:
- Teams decided transition defense was more valuable. The most obvious assumption, I think. A possession lost in transition is expensive, and sending bodies to the glass makes it harder to defend.
- A missed three bounces out longer and less predictably than a missed two, and five-out spacing has the offense standing 25 feet from the rim when the shot goes up. Even a willing crasher starts further away and arrives later. This would mean effort never changed at all.
- The second big went away. Two-big lineups and offensive-rebounding specialists thinned out, and the center who used to stand under the rim now stands at the arc. Though this one has turned around lately: Sportico reported lineups with three or more players 6-9 or taller at 11.1% of minutes recently against 5.0% in 19-20, the same stretch where offensive rebounding came back.
The middle one I could actually test. Box scores never record which shot a rebound came off, but play by play does, so I went back through every missed field goal since 96-97, paired it with the rebound that followed, and split by whether the miss was a two or a three.
The share of those misses that the offense gets back is what I'll call the recovery rate. That's the first two columns:
| Season | Missed twos the offense got back | Missed threes the offense got back | Share of misses that were threes |
|---|---|---|---|
| 96-97 | 33% | 30% | 24% |
| 20-21 | 27% | 19% | 47% |
| 25-26 | 29% | 24% | 50% |
Missed threes really are harder to get back, and that gap is there in every single season, so that part of the theory is true. But it isn't what caused the drop.
Two different things are moving in that table. How often each kind of miss gets recovered, the first two columns. And which kind of miss it is, the third. If the shift to threes were doing the work, the first two columns would have held steady and only the third would have moved. Instead the first two fall too. Teams went from getting 33% of missed twos back to 27%, and twos are the shot the three-point boom was supposed to leave alone.
So which of those two did the damage? You can check by changing one at a time.
Picture a league that takes today's shots but rebounds like 96-97. Nearly half its misses are threes, but it still gets back 33% of missed twos and 30% of missed threes. That league recovers 31.6% of its misses. The real 96-97 number was 32.1%. So the entire shift to threes is worth half a point.
Now the other way. A league that takes 96-97's shots but rebounds like 20-21. Only a quarter of its misses are threes, but it gets back just 27% of missed twos and 19% of missed threes. That league recovers 24.8%, down 7 points.
The real fall was 9 points, 32.1% to 22.9%. So half a point of those 9 is the shift to threes, about 7 is teams getting worse at recovering every kind of miss, and the last 1.3 is the overlap between them. (recovery rate by shot type)
The last five years say it again, reversed: threes went from 47% of misses to 50%, so that third column kept pushing offensive rebounding down, and it went up anyway.
So threes are part of this, but nowhere near most of it. Something else did the rest, and I still don't know what.
Two objections.
First, spacing: even when the shot comes from the same spot, the four guys who aren't shooting may be standing further from the rim than they were in 96-97, so the offense starts every rebound a step behind. I can't check it. Nothing records where players stood until tracking starts in 13-14, by which point the recovery rate had already fallen from 32% to 26%.
Second: splitting misses into twos and threes holds the shot's value fixed, not the shot. The mid-range died while attempts at the rim grew, so a missed two in 25-26 is a different mix of shots from a missed two in 96-97, wearing the same label.
So I ran it. Play by play carries shot coordinates from 10-11 on, so you can hold the spot on the floor fixed instead of the shot value. Over 10-11 through 19-20:
| Misses from | Recovery, 10-11 | Recovery, 19-20 | Fall over the 10 years |
|---|---|---|---|
| 3-8 feet | 33.2% | 29.8% | 3.8 points |
| 10-20 feet | 22.1% | 19.4% | 4.1 points |
| everywhere (all misses) | 27.5% | 23.2% | 5.4 points |
Location is not nothing: the rate on all misses fell 5.4 points (that column is a trend across all ten seasons, not the first two subtracted), and 3.8 to 4.1 of it survives holding the spot on the floor fixed. Call a quarter of it shot location, and three-quarters something that happened to shots from the same place. Note the mid-range row: it's the worst place to miss from, worse than the arc, so "longer shot, longer bounce" isn't even right as physics.
So what's ruled out is "missed threes bounce further and there are more of them now", and most of "shots moved to places that rebound worse". Not geometry in general: the spacing idea is untouched, and this check only covers 10-11 onward, about half the fall.
Back to the share graph near the top: it's risen for the last 5 years and I have no idea why that is either. Size coming back, teams deciding they'd overcorrected on transition defense, everyone copying whoever tried it first: all plausible, none of it something I can show with this data. That's a different post.
All the above links are to graphs that I think help make this more clear.
Things I referenced:
- The big-lineup numbers: Sportico, "2025 NBA Season: Teams Are Crashing the Offensive Glass in Preseason"
- Mid-range being the worst place to miss from is not my finding: a 2012 Sloan paper, Maheswaran, Chang, Henehan and Danesis, "Deconstructing the Rebound with Optical Tracking Data", and Todd Whitehead's hand-tracked study, Nylon Calculus, "More lessons from NBA rebound tracking"
- The data: NBA.com stats, pulled with nba_api
I did use AI for this post. All the calculations were done in python on my computers from data gotten from nba.com. I've done to make it as readable as possible.