NBA teams are — by rule — prevented from running true zone defenses. The defensive three second violation was put in place specifically to prevent zones from clogging up the paint and slowing down the game, and as a result, even though most teams utilize some sort of zone coverage in pick-and-roll situations and the like, more explicit zone schemes have become a rarity. Practice time all presents a significant hurdle, as most NBA teams just don’t have time to implement their full offensive and defensive packages with a separate zone set on top.
The Dallas Mavericks are the exception. Over the last few seasons, Rick Carlisle has implemented a match-up zone scheme that was at first used sparingly, but has since become a regular part of the Mavs’ defense this year. The zone has been quite successful, but with such atypical approaches, there’s always a worry of a regular season smokescreen. Just as most teams don’t have time to install their own zone sets, they also don’t have time to specifically address how to counter them. The time just isn’t there in between regular season games, and thus the Mavs have been able to catch quite a few opponents off-guard with extended use of the zone. Given the spaced out schedule of a playoff series however — not to mention the singular focus of only having to play a single opponent at a time — it’s widely assumed that opponents will be more effective in their teched-out counters.
Only time will tell, as Dallas has never been this good at using the zone in past seasons, and never leaned on it quite as frequently. Sebastian Pruiti — also of NBA Playbook, amid myriad other sites at which he contributes — took a closer look at the Dallas zone for a feature at Basketball Prospectus:
There hasn’t been a team that has used the zone for long stretches and been successful. That is, until this year.
According to Synergy Sports Technology, the Mavericks have played zone defense 12.8 percent of the time this season, by far the most often in the league and more than double that of the Trail Blazers, second at 5.8 percent. Seeing and expecting the zone is one of the keys to being able to beat it. Yet, Dallas opponents seeing the zone multiple possessions per game, the Mavericks remain very effective running this defense. They’ve allowed just 0.85 points per possession on 39.8 percent shooting from the field.
In fact, even though the Mavericks play so much zone, they still have posted a top 10 defense in terms of Defensive Rating (102.3, ninth in the league). One of the main reasons you don’t see teams run a lot the defense is because you can’t run a standard zone in the NBA because of the defensive three second rule. Teams struggle with this concept and instead of trying to work through it, they just abandon the zone as a primary defensive concept.
The Mavs’ execution of the zone is worth an even closer look, so follow along to Basketball Prospectus to read Pruiti’s breakdown in its entirety.