Dallas’ defense has been impressive through this four-game win streak they have reeled off to start the new year, holding all four opponents to under 100 points, an impressive feat in the modern NBA. I’ve been particularly impressed with the readdition of Luka Doncic and Tim Hardaway Jr. defensively the last three games, as I thought those two returning would immediately result in worse defensive performances. This improved defensive stretch reaches back 15 games, with the Mavs boasting the third-best defensive rating since their game against Memphis on December 8. However, I believe a significant part of this uptick defensively has little to do with the Mavs themselves, but rather resulting from poor opposing shooting from the corner three.
The three most valuable shot locations for any offense are the free throw, layup, and corner three, and limiting those opportunities is one way to have an elite defense. On a positive note, the Mavs are limiting their opponent’s trips to the line, as opponents' free throw rate is dramatically down from a high water mark from December 19 to the 27th, where opponents got to the line whenever they wanted.
During this win streak, the only outlier in preventing trips to the line comes from the Nuggets, where Jokic, Campazzo, and JaMychal Green were able to get to the charity stripe a combined 15 times, certainly less than ideal. In their other three wins, the Mavs were able to avoid sending their opponents to the line, limiting high FTA players like De’Aaron Fox and Steph Curry to below their season averages. Staying in front of these explosive players and forcing them to earn every bucket is important to developing an above-average defense, something I can praise the Mavs for recently. However, this doesn’t fully explain the improved defense over 15 games, as the high watermark I spoke of earlier happened right in the middle of this stretch. Dallas’ turnover percentage on defense isn’t the reason either, as throughout this 15 game stretch the Mavs are below league average more often than not, with the most recent two games being the two best for generating turnovers.
One variable I think has impacted defense is the prevention of offensive rebounds, up from a low point in early December. Preventing extra possessions has to be a priority, and while the numbers have improved, three of the best performances in that area came in losses to the Lakers, T-Wolves, and Bucks. While no single variable leads to improved defense, I think that opponents' poor shooting is the biggest indicator of their recent performance.
Using game log data from Cleaning the Glass it becomes apparent the level of poor shooting the Mavs are benefiting from. Through the past four games, opponents are shooting just 28% from corner threes, a full 10% below the current league average for the season of 38%.
This trend of poor shooting from the corners stretches back to December 8, as throughout the last 15 games opponents have hit just 30.9% of their corner threes, certainly contributing to Dallas’ number three defense in that stretch. Perhaps this regression to the mean was bound to happen, as the Mavs had been victim to some scorching shooting to start the season, but I wouldn’t rely on this to continue throughout the year. Perhaps more alarming is the sheer volume of these shots the Mavs give up, with opponents seemingly getting looks in the corner whenever they want. Throughout the winning streak and last 15 games, they are routinely allowing high numbers of these high percentage looks, with 11 out of the 15 games resulting in an above league average volume from the corner from their opponents. Opponents aren’t hitting shots they usually make, leading to inflated defensive results for Dallas.
If Golden State had shot their season average both above and below the break they would have made one additional corner three, but a whopping four more non-corner threes, leading to a 15 point swing. If you exclude garbage time that’s enough to flip the result in favor of the Warriors. A loss against the Bucks would have been much worse had Milwaukee not shot 1/9 from the corner, and the win to start this 15 game stretch against Memphis could have gone the other way had they not missed all of their corner threes. Teams aren’t going to continue missing these shots for the rest of the season, and if the Mavs continue this trend of giving them up I fully expect the defensive performance to come back down to Earth, as it's not sustainable to rely on poor opposing shot-making.
I wanted to take a look at what the data said about this recent improvement in the Mavs defense, as watching the games it was apparent that opponents weren’t making the shots you’d expect them to. Game-to-game three-point shooting in the NBA is very random, with trends only emerging over longer stretches. I think that over the past 15 games there is enough data to suggest that a significant part of the Mavs number 3 defensive rating is due to poor opposing shooting from the corners, with opponents shooting well below league average since December 8. If the Mavs were limiting the numbers as well as percentage of these shots I’d argue that it’s a result of impressive defense, but I can’t help but feel Dallas is just getting lucky with poor shooting. This high volume of corner three’s probably isn’t sustainable and I’d expect to be buried at some point when team’s start hitting them. I’m hoping to be proven wrong and for this defense to be legit, but I’ll err on the side of caution with a team that has been below league average defensively the past couple of years, with largely the same pieces they have now.