Get To Know An Advanced Stat: Rebound Rate
If you're not into advanced stats, you'd probably assume that rebounding is one of the last safe havens from our nerdy evaluation metrics, but you'd be wrong.
For as long as basketball has been played, evaluating how well a player or team rebounds has been pretty simple. Just total the number of rebounds the player in question or the team in question grabs in a game, grabs per game or at the most advanced, how many he grabs per minute to eliminate the advantages that players who play heavier minutes would have.
Furthermore, the basic stats will also keep track of how many of the rebounds grabbed were offensive boards and how many were defensive.
But even still, in a stat category that seems almost too simple to complicate, we now know that there is a better way to evaluate how well a player or team rebounds the ball, and that's with rebound rate. The formula seems intense but the premise is actually pretty simple - it's a measure of the percentage of available rebounds (missed shots) a player grabs while he's on the floor or the percentage of available rebounds a team collects as a whole.
The basic flaw with measuring rebounding by the total number of boards collected is that it doesn't take into account how many rebounds are actually available to be collected. For example, if a team has a hot shooting night and makes an insane amount of their attempted shots, there will naturally be less defensive rebounds to collect for the opposing team and less offensive rebounds to collect for the team in question.
If a team plays the game at an extremely slow pace and takes less shots in general, leaving less opportunities for rebounds to hit the air, should the players on the floor be punished in their stats because they couldn't grab non-existent rebounds?
What about a player who comes in off the bench during a game with plenty of rebounding opportunities, but is suddenly devoid of such opportunities in the small sample of minutes he plays? Again, rebound rate wouldn't punish him for it, because all it is measuring is how many of the available rebounds while he was on the floor - no matter how many or how few - he was able to grab.
For a team, it's the same premise, but without the need to distinguish how many boards were available for different players. Just take the number of rebounds a team grabs and divide it by the total number of rebounds in a game. Voila, team rebound rate.
Of course, rebound rate is also broken down into offensive rebound rate and defensive rebound rate, and I'll remind you that a team's offensive rebounding percentage (and that of their opponents) is actually one of Dean Oliver's 'Four Factors' of basketball success.
Right now, Dwight Howard, Kevin Love, DeAndre Jordan, Andre Drummond and Nikola Vucevic lead the NBA in rebounds per game (11.4-14.2 from Vucevic to Howard), but opening up the rebound rate category is a much better measure of the most productive rebounders in the Association. Reggie Evans and his rebound rate of 21.3 joins the conversation in the No. 3 spot, Jordan Hill and his 20.8 rebound rate come in at No. 4, and Vucevic actually comes in at No. 18 with a rate 18.1 - excellent, but not quite top-five material.
My favorite early season rebound rate belongs to Jazz rookie center Rudy Gobert. The 21-year-old Frenchmen is grabbing an astonishing 23.2 percent of available rebounds in his 11 minutes per game as a first year player. To put that in perspective, Dennis Rodman's career rebound rate is 23.4.
The best part is that with SportVU tracking now available in every NBA arena, the way we evaluate rebounding has actually further evolved. NBA.com's new rebounding categories under the Player Tracking section takes 'advanced' to a new level.
For example, they consider a rebounding opportunity to be when a player is within 3.5 feet of an available rebound, and that opens our eyes to a couple of things. First, Kevin Garnett if nothing else is still rebounding exceptionally well, as of players with at least six games played and 10 minutes per game so far this season, Garnett's rebound rate within 3.5 feet leads the pack at 79.5. In addition, while I don't want to take away from their rebounding prowess, it should be noted that Kevin Love and Dwight Howard average more rebounding chances per game than any other players (per NBA.com), though that can also be a testament to their instincts and positioning for a board when a shot goes up.
Most shocking, though, is that historically bad rebounder Andrea Bargnani actually grabs 73.2 percent of such rebounds (within 3.5 feet), which gives credence to the argument that his tendency to drift around the perimeter on offense and get lost on defense is the reason his rebounding totals are so low, not because he's physically incapable or too 'soft' to actually jump up and grab a ball out of the air.
And if you want to take rebound rate even further, NBA.com is now tracking the difference between contested rebounds and uncontested rebounds, where a contested rebound is considered to be a rebound grabbed with an opposing player within 3.5 feet. Remember how I told you Howard is among the leaders in rebounding chances per game? Well of the top-40 rebounders when it comes to basic rebounds per game, Howard has the lowest percentage of those being contested rebounds, at 28.2. As a comparison, 45.9 percent of Andre Drummond's 12.1 rebounds per game have been contested, while 60 percent of Enes Kanter's 7.3 rebounds per game have been contested.
Personally, I'd like the next step to be measuring what percentage of contested rebounding chances players collect as opposed to what percentage of their total rebounds are contested, but nevertheless, the point is that we're clearly getting there.
I'd understand the reluctance to join this growing NBA stats movement if there was a pay wall in front of the best stuff or if finding such advanced metrics took too much time out of your busy schedules, but finding all of the rebound rates I've mentioned above is now as easy and as free as finding the older fashioned basic rebounding numbers, so if you strive to better understand the game, why not take advantage of it?
Rebounding might seem a simple art, and in many ways it is, but if we're going to dig deeper to evaluate how well teams and players score the ball, we should do the same for how they rebound it, and now we can.
(All stats courtesy of NBA.com and ESPN.com/Hollinger)
For more in my Get To Know An Advanced Stat series, check out Offensive/Defensive Rating and Effective Field Goal Percentage/True Shooting Percentage.