Terry Rozier's Defensive Impact

Terry Rozier has the fifth highest defensive rating in the league. Is he really a great defender, or does he just benefit from being surrounded by other great defenders?

The Boston Celtics have gone more than a month without a loss in large part due to their defense. Their ability to switch seamlessly on nearly any defensive assignment has allowed them to transcend one of the most fundamental challenges to any NBA team, which is finding a way to overcome unfavorable matchups.

Per NBA.com, Boston’s 95.8 defensive rating leads the NBA, which is made possible not only by switching but by their immensely improved rebounding. Their 82% defensive rebounding rate leads the NBA as well, which could be responsible for their league-fewest 9.4 points per game surrendered to second-chance points.

In several individual defensive metrics, the top of the list is littered with Celtics. The top four players in defensive win shares, for example, are all Celtics: Jaylen Brown, Jayson Tatum, Al Horford, and Kyrie Irving, in that order (via basketball-reference). Seven of the top 10 in defensive rating play for Boston, which includes the same four players listed above along with Aron Baynes, Terry Rozier, and Marcus Smart. And this is where I hesitate to trust the numbers. Is Terry Rozier really a good defender? He doesn’t have the length to switch on so many matchups like his teammates, so how does he fit in?

Here’s an interesting stat that could provide an answer: when it comes to individual defensive rebounding percentage, you will find zero Celtics in the top 20, even with the league’s best team rating. It would be easy to point at Al Horford as a weak link, but he’s actually having a renaissance year on the boards, and his 8.8 per game currently has him at 19th in the league. So, where does all the rebounding come from?

If you look at the rebounding averages of the Celtics roster, you’ll find that it’s pretty balanced. There are seven players that average between 4.4 and 6.7 rebounds per game, and Rozier’s 4.8 doesn’t exactly stand out, but it’s actually exceptionally efficient for a point guard his size. Per NBA.com, Rozier is fifth among all players under 6’4”, trailing Russell Westbrook (8.7 RPG), Kyle Lowry (5.4), Damian Lillard (5.3), and Stephen Curry (5.2). All of a sudden, we find Rozier in unexpectedly elite company. Also of note: those four guards ahead of Rozier play an average of 33.7 minutes per game, while Rozier only plays 23.7.

When it comes to rebounding, positioning is key. Unless you're Terry Rozier.