Stat Watch: The best defensive rebounding teams in the NCAA

Who is the best defensive rebounding team in the country? Most people would probably guess Baylor and with good reason.  In ESPN’s Around the Rim podcast, LaChina Robinson asked if their bigs Lauren Cox and Kalani Brown were the best 4/5 combination in women’s basketball this season because the pair have been dominant.  Among their many statistical highlights, both Cox and Brown are among the top 50 players in Division I in defensive rebounds per game.
As a result, Baylor leads the NCAA in defensive rebounds per game by a wide margin. As the table below shows, they are #1 in the country averaging 34.6 defensive boards a game. The gap between Baylor and the second-ranked Dayton Flyers at 31.3 defensive rebounds per game is the same as the gap between Dayton and 42nd ranked Portland State at 28.0.

Top Divison I teams by Defensive Rebounds Per Game

But is Baylor really the best defensive rebounding team by such a wide margin? Actually, no.  Her Hoop Stats launched this fall to ensure that the women’s basketball community has reliable and easy access to both traditional and “advanced” statistics about the women’s game.   The advanced statistics have become widely accepted over the last decade in the NBA and men’s college basketball and in most cases are quite intuitive.  They’re often as simple as the change from batting average to on-base percentage in baseball.
In our case, what makes Baylor’s defensive rebounding numbers so high? Of course, they are great at securing the rebound.  However, their defensive rebounds per game benefit from the fact that they play at a relatively fast pace, ranking in the top 20% of the country in possessions per 40 minutes.  More importantly, they are the best in the country in opponent FG% (31.1%) and amazingly their opponents are shooting the fourth-lowest rate from the charity stripe as well.  That means there are many misses by their opponents and so tons of opportunities for Baylor to pull down the rebound.
A better way to measure their performance on the defensive glass is with the statistic “Defensive Rebounding Rate”.   This metric is simply the percentage of chances a team (or player) has for a defensive rebound where they successfully corral the ball.  As an example, in their 81-56 win against Texas on January 25th, Baylor pulled down 34 of the 48 opportunities they had for the defensive rebound.  That means their defensive rebounding rate was 34/48 or 70.1%.  In contrast, the Longhorns’ defensive rebounding rate was 20 of 36 or 55.6%.
So, is Baylor the top team in the county in defensive rebounding rate too?  Not quite.  With a defensive rebounding rate of 76.3%, they are actually second behind NC State. The Wolfpack are pulling down 77% of all available defensive rebounds.  Why aren’t they included in the list above of the top 5 teams in defensive rebounds per game?   NC State plays at a pace that is in the slowest third of Division I and their opponent FG% is low (25th best) but not quite as low as the aforementioned teams.
The chart below plots defensive rebounds per game and defensive rebounding rate for all 349 Division I women’s basketball teams.  As you can see, the Green Bay Phoenix are perhaps an even more extreme case, ranking 3rd in defensive rebounding rate but 88th in defensive rebounds per game. In contrast, Dayton, Tennessee, and Iowa all rank significantly lower in defensive rebounding rate than they do in defensive rebounds per game.

Defensive Rebounds Per Game vs Defensive Rebounding Rate for all NCAA Division I Women’s Basketball Teams

They are many steps along the path from the traditional per game statistics to the most cutting-edge statistics in the NBA that are being developed by Ph.D.s using machine learning.  Defensive rebounding rate is a great example of a simple adjustment that can be made to traditional basketball statistics to better understand the game.  Her Hoop Stats and The Summitt are looking forward to bringing more statistical insight to the women’s game for the rest of the season.