On the whole, offensive rebounding is on a downward trend in the NBA. Zach Lowe wrote on this recently, but something else is happening relating to transition defense. There has been a noticeable a rise in transition defense efficiency. As a whole, the league average for points per possession in transition has dropped from 1.71 to 1.64. Teams are focusing on preventing points in transition, to the demise of offensive rebounding it would seem.
A natural assumption is that the teams that are ranking highest in offensive rebounding are sacrificing transition defense to do so. But, the data shows the opposite. Take the top 9 teams in Offensive rebounding %.
|ORB%||Team||PPP allowed||Transition Def Rank|
The average of their transition efficiency would rank 9th in the NBA. Obviously this a rough measure, but it shows that good offensive rebounding and good transition defense aren't mutually exclusive.
This is where the Celtics come in. Boston is one of the few teams to improve both their offensive rebounding percentage and transition efficiency this season. They rank 9th in offensive rebounding, while ranking 3rd in transition defense.
The transition defense isn't surprising, as Boston's defense has been strong all season. The Celtics are just built well for transition defense. Boston has a collection of great athletes that give good effort and energy. Plus, the versatility of guys like Jae Crowder and Marcus Smart makes it easy to switch on the fly if needed.
But the improvement on offensive rebounding is a little surprising given that they were slightly below league average last season. It makes sense once you listen to Brad Stevens though. Unlike some coaches, Stevens is not one to throw away chances for extra possessions. He gave some insight into his thinking in Lowe's article.
"It's something we're all struggling with... [t]eams all place a large focus on defensive rebounding. If that's important, then offensive rebounding must be important, too."
This shows up statistically. Per Nylon Calculus, the Celtics are 6th in OREB "chase percentage", a statistic that measures how often a team goes after an offensive rebound. The Celtics are fairly aggressive, but not reckless going for offensive rebounds.
For the most part, the Celtics don't take too many unnecessary chances. If someone is in good rebounding position, they'll fight for it. Otherwise the player will just drop back into transition defense. That is unless, you happen to be Marcus Smart. He has an incredible ability to fly into the paint and snag rebounds. Look at this play for instance.
It's a typical-looking missed shot, and then Smart comes out of nowhere to dunk over Julius Randle. His offensive rebounding percentage is 4.6. That doesn't jump off the page until you compare it to other guards. This season, only five other guards can top that number. That includes Wade, Westbrook, and former Celtic Tony Allen. The other two are Shabazz Muhammed and Andre Roberson, both of whom are over 6'6". The point is, Smart is in elite company as far as rebounding goes. Giving Smart the freedom to make plays like this reflects well on Stevens. It shows that like any great coach, he's willing to give players the chance to make the best of their skills.
Overall, the best offensive rebounder on the Celtics is Jared Sullinger. As you'd expect, Sully leads the team in all rebounding categories. He's not grabbing offensive rebounds quite at the level he was a few years ago, but he's still productive on the glass.
Amir Johnson is right behind him, and Tyler Zeller (in limited minutes) is in the mix as well. But nobody on the Celtics is even in the top 25 for ORB% in the NBA. So how does Boston rank so highly in offensive rebounding? It may feel like a cop-out, but the best explanation is team rebounding. All these advantages on the margins add up.
It fit thematically with the story of this team too. All season we've heard about the whole being greater than the sum of its parts. This is another example. The Celtics don't have a generational talent like Drummond to lean on, so everyone has to chip in. Whether its Smart miraculously stealing rebounds off free throws, Jonas Jerebko hustling to tip the ball to teammates, or the steady force of Sullinger down low, everyone does their part.
With the league moving away from offensive rebounding, the Celtics have an opportunity to take advantage. Being able to generate extra possessions without sacrificing on defense is huge, and the Celtics are seeing the benefits of that this season.