Offensive Rebounds: What Are They Good For?

Here's a topic we've discussed before on Canis Hoopus: what is the meaning of offensive rebounding?  Does it negatively effect transition defense?  Does it actually help you win?

We've talked about this because between Kevin Love and Nikola Pekovic, the Wolves have two of the best offensive rebounders in the NBA.  And if they are healthy and play significant minutes together, the Wolves could emerge as one of the league leaders in offensive rebound rate.

I bring this up again because Zach Lowe discussed the issue yesterday at Grantland.  His article, like most of his pieces, is quite illuminating.

It focuses primarily on the Indiana Pacers, and their success both on the offensive glass and in transition defense.  Lowe comes to two interesting conclusions:

First, that there is no evidence that strong offensive rebounding correlates with poor transition defense.  Looking at several measures, he concludes that the best offensive rebounding teams are essentially average in transition opportunities allowed and points per fastbreak.

Second, "...the correlation between offensive rebounding and winning is still very low, according to several stats experts around the league."

This second conclusion, the lack of correlation between offensive rebounding and winning, is not so clear-cut.  Lowe himself quotes a study from the MIT Sloan conference that teams are leaving several points on the floor by not crashing the offensive glass harder, and our own Madison Dan has found that an increased offensive rebounding rate does add wins, even though it is also associated with a slight increase in opponent TS%.  Dan found that one standard deviation increase in offensive rebound rate means an extra 2.56 wins per season, which is quite significant.

However, accepting for the sake of argument that there is limited correlation between offensive rebound rate and winning, it doesn't mean that all other things being equal, being a better offensive rebounding team won't help you win.  It does suggest, however, that all things aren't equal for most good offensive rebounding teams.  The question is whether and what these teams are giving up (or are incapable of) such that their offensive rebounding doesn't make up for it..

One might posit that, for some reason good offensive rebounding teams are on the whole bad offensive teams that miss a lot of shots.  Though we are discussing O-reb as a rate, not a count, it might be that the skills that lead to offensive rebounding correlate with poor shooting skills, and/or that teams that miss a lot are forced to expend more effort on the offensive glass in order to score at all.

Hopefully, this won't be true of the 2013-14 Wolves.  One of the things Lowe discusses is when and how teams send a third player to the offensive glass (the Pacers, and presumably other teams, have fairly sophisticated on court decision-making systems in place for this).  The Wolves, on the other hand, are blessed with two tremendous offensive rebounders, and may not need too much extra help to be above average on the offensive glass.

Lowe touches on the Wolves in this context with the following:

...Wiens and her team found two teams changed their offensive rebounding philosophies dramatically between 2011-12 and last season: Minnesota and Washington. The Wolves appear to have sent an extra player, on average, to chase offensive boards, while the Wiz focused more on transition defense, Wiens says.

The Wolves nugget speaks to the importance of personnel. In 2011-12, they had Kevin Love, one of the world’s great offensive rebounders. Love missed most of last season, and the team shot a pathetic 30.5 percent on 3-pointers. When you have Kevin Love, you can sustain on the offensive glass without over-pursuing. When you don’t have Kevin Love, you might need to send an extra player, especially when you know you are a horrible shooting team that needs extra chances to survive.

It's interesting to note that the Wolves offensive rebounding percentage was nearly identical in 2011-12 (27.5%) and 2012-13 (27.4%), though it was further above league average in 2012-13, the year they primarily operated without Kevin Love (and Nikola Pekovic's individual O-Reb% was lower).  This indeed suggests that they were sending extra players to the boards to secure second opportunities, as the quoted study found. It also leaves open how they will approach the offensive glass this season, with their two monster rebounders on the floor.

With any luck (read: health) the Wolves will be an above average offensive rebounding team without consistently sending a third player to the glass, and will be even more effective when and if they choose to do so.  Despite the lack of clarity on the value of offensive rebounds (though I'm inclined to take Madison Dan's word for it), I hope the Wolves do excel in this area. I admit that I am now entering the world of wild speculation, but I wonder whether their aggression on the offensive glass doesn't contribute in other ways, such as their (relatively) new found ability to draw fouls, and hence get to the free throw line.

If the Wolves are a good team this year, it will be because they score efficiently, driven by free throw attempts and much better three point shooting, and rebounding at both ends of the floor.  A significant amount of the offense (read: scoring) produced by their two best returning scorers, Love and Pekovic, is generated from offensive rebounds. For example, last season 18.4% of Pek's used possessions came from offensive rebounds. He scored 1.17 points per possession on those, had the lowest turnover% of any category of his used possessions, and shot 57% on them.

The Wolves, a flawed team,  have one advantage over most teams in the NBA: they have two players who are capable of dominating the paint on the offensive end, and this includes scarfing up a large number of their own misses. If they want to be a playoff team this year, they will have to use this advantage, because they don't have an endless supply of them.

It might be that this is not the most efficient way to be good in the NBA.  But it's what we've got.  After a decade of basketball ranging from disappointing to historically awful, we are in no position to be choosy.