Is Rebounding a Problem?
Posted by Zach Lowe on Nov 23, 2009
Red’s Army called for some calm today in discussions of the C’s perceived rebounding problems. Red’s pointed out that the C’s are actually out-rebounding opponents by a slight margin (39.0 to 38.7 per game). Even more interesting: Red’s made the claim that there are fewer rebounds total in a Celtics came than there in an average NBA game.
Red’s was even more right on the money than he/they realized: No team’s games feature a lower average rebound total than Boston’s. An average C’s game has 77.7 rebounds—the sum of the C’s average total boards (39.0) and their opponent’s average total boards (38.0).
No other team has an equivalent total rebounding average below 80 per game, according to ESPN’s stat page. The closest: Miami. The Heat grab 40.6 boards per game, and their opponents take down 39.7—a total of 80.3 rebounds.
So, weirdly, the C’s games are bereft of boards. Why?
1) Pace—only four teams average fewer possessions per 48 minutes;
2) Shooting skill—only two teams (Phoenix and Golden State) make more of their shot attempts than Boston. More makes=fewer defensive rebounds for opponents.
3) Turnovers—The C’s so far have forced more turnovers per possession than any other team in the league, and they are still coughing the ball up at a high rate. More turnovers=fewer shots=fewer rebounds.
The question follows: If there are fewer rebounding opportunities in a Celtics game, does it mean the C’s rebounding problems aren’t a concern?
Of course we should be concerned, and Red’s doesn’t say we shouldn’t be—not at all. But the raw rebounding numbers Red’s mentioned today (that 39.0 to 38.7 stat) actually show how misleading simple raw rebounding numbers can be. You’ve got to look at the percentages of available rebounds a team gets. Doing that takes away (mostly) the effect of all the variables we brought up before—pace, shooting ability, turnovers, etc.—and asks a pretty simple question: Of all the available rebounds in a game, how many does your team get?
And that’s where we see the C’s glaring rebounding problem: Offensive rebounding. The C’s are squeezing 24 percent of available offensive rebounds; only four teams (Cleveland, Orlando, Golden State and the Knicks) are worse. Last year, the C’s were 8th-best in this category, with a solid 27.9 offensive rebounding rate.
That is a huge, huge drop, and we’ve discussed the reasons for it in several other posts. (Hint: Sheed and age).
What about defensive rebounding? There, the C’s are fine–s0 far. The team has grabbed 75.1 percent of available rebounds under their own basket—good for 9th in the league. That’s a nice relief after the C’s sank into the bottom half of the league a week ago due to those disastrous board performances against Atlanta and Utah.
One caveat: Boston’s schedule has been loaded with the worst offensive rebounding teams in the league, meaning the C’s have put up that 75.1 percent figure against little resistance. In their first 14 games, they’ve already faced #s 18, 22, 23, 25, 27, 28, 29, and 30 in offensive rebounding rate.
Can the C’s keep up their defensive rebounding when they begin to face more of the better offensive rebounding teams in the league? The answer will be absolutely crucial to their lon-term success.
So, Red’s is basically right: The C’s are an average rebounding team—solid on the defensive end, awful on the offensive end. I’m a bit more concerned about the latter than the guys at Red’s appear to be. Here’s why: The C’s offense, as it is functioning now, essentially has one way to score—create an open look in the half court and knock it down. They don’t grab many offensive boards, they rarely get to the line (the C’s rank 23rd in the ratio of free throw attempts to field goal attempts) and they don’t score a lot of points in transition.
We saw against Orlando what happens when a good defensive team prevents the C’s from getting open looks in the half court—the C’s don’t score. They had nothing to fall back on against the Magic. Denver is such a dangerous offensive team because the Nuggs get to the foul line more than anyone; if the Js aren’t falling, they can find another way to score. The Rockets are 6th in the league offensive efficiency, thanks partly to their stunning offensive rebounding rate (29.5 percent).
Of course, the C’s shoot the ball so well because their offense is well-designed and the players executing it are really good. But when you’ve got one game in June you’ve got to win, it’s nice to have another way to score when the rhythm is gone or the opponent’s defense is stifling.
And right now, the C’s don’t.