Why Everyone’s Playing Zone All of a Sudden
Scroll to the end for some good data viz with minimal commentary
One of the more interesting developments in this year’s playoffs has been the frequent use of zone defense. Teams like the Miami Heat have been playing zone defense for year, but in this postseason, newcomers are using it more frequently to disrupt modern offenses that have gotten too good at picking apart traditional defenses.
Nowhere is this dynamic more apparent than in the series between the Oklahoma City Thunder and Denver Nuggets. The Nuggets have played zone defense against the Thunder on a grand total of 30 percent of their halfcourt possessions, according to Second Spectrum tracking data. For context, the Nuggets played zone defense on just five percent of their halfcourt possessions in their first-round series against the Clippers and just three percent during the regular season.
Sunday’s Game 4 was the high watermark for the Nuggets' use of this type of defense. Denver played zone on nearly 70 percent of their halfcourt possessions. It was by far the most they’d play zone in any game — regular season or playoffs — this season.
In some ways, the zone worked. The Nuggets held the Thunder to 92 points and OKC players, at times, looked out of sorts trying to attack Denver’s shell. Zone defenses encourage the offense to move the ball with passes instead of dribbles, which might make a team like the Thunder uncomfortable given they were 25th in passes made per game during the regular season. The Thunder’s strategy of giving the ball to SGA and letting him cook loses some of its punch when there are five defenders ready to collapse on him as soon as he touches the paint.
Still, the Thunder did enough to come away with the win and now the series is tied 2-2, heading back to Oklahoma City for Game 5 tonight. Now the question is will the Nuggets rely on the zone again or will they turn to something else?
We’ve seen more zone defense in these playoffs than in any postseason in recent memory. The chart below shows the percentage of halfcourt possessions where zone defense was played each season. I’ve broken it out by regular season and playoffs since the 2013-14 season, the first year tracking data became available.
Before this year, the percentage of possessions in the playoffs featuring zone defense was largely a function of how deep of a postseason run the Miami Heat could make. 2020 was the year Miami made the NBA finals by flummoxing opponents with their zone defense and ever since then more teams have started experimenting with the zone. The uptick in zone frequency in this postseason is notable for the fact that Miami was eliminated after just four games in their first-round series against the Cleveland Cavaliers.
In these playoffs, it’s teams like the Nuggets, Cavaliers, and Warriors that are using zone principles to help solve their defensive problems. The chart below shows how often each playoff team has played zone in the postseason compared to the regular season.
Miami played zone more than anyone else during the regular season, but both the Nuggets and the Houston Rockets (who were eliminated by the Golden State Warriors in the first round) have outdone the Heat in the playoffs.
But is it working?
The Thunder have scored 108 points per 100 possessions against Denver’s zone in the halfcourt. Meanwhile, when Denver plays man defense, the Thunder are scoring….108 points per 100 possessions. Still, league average offensive efficiency is almost five points per 100 possessions lower against zone defense compared to man defense in these playoffs.
So there’s some evidence that zone defense can be a viable alternative to man defense, but there are caveats.
For example, as we’ve already shown, not every team is playing zone. It could be the case that better defenses are more inclined to experiment with zone thus skewing the overall averages. Further, not every team that is playing zone defense in these playoffs is facing the same caliber of opponent. It’s possible the teams that are playing zone are doing so because they know their specific opponent will struggle to attack it. And finally, teams are only playing zone on less than five percent of all possessions. That’s not that much! In other words, our sample in this year’s playoffs is both probably biased and small.
In the regular season, where the samples are larger and more diverse, we see that teams actually play a tiny bit better against zone defenses than man defenses. This year, in the regular season, the league average Offensive Rating was 112.7 against zone defenses compared to 112.1 vs. man defense in the halfcourt.
Even though there aren’t substantial efficiency differences between zone and man there are substantial stylistic differences. For example, zone defenses have a radical effect on an opponent’s shot selection. You can see this in the Rim Rate columns below. Teams typically take more than 20 percent of their shots at the rim against man defense, but that number drops by several percentage points when the defense is in zone. If your team bleeds points in the paint, or lacks a traditional rim protector, then dropping into zone might make sense.
The tradeoff, however, is that offenses can shoot the defense out of a zone by bombing threes. That might have been sub-optimal from a defensive perspective in an earlier version of the NBA when offenses weren’t taking enough threes to begin with. But now that the league average three-point rate is well above 40 percent, how much do those extra threes really hurt you?
Denver appears to have made a bet that a few extra Thunder threes won’t hurt that much and it’s a bet they’ve mostly won. Jalen Williams, Chet Holmgren, and Lu Dort are shooting a combined 23 percent (16/71) from three through four games after shooting a combined 39 percent from three in the regular season.
Another feature of zone defense is that it weakens your opponent’s isolation game. The zone forces players that tend to dribble the air out of the ball to trust their teammates and the pass. That can cause problems for players that are used to scoring by beating their man off the dribble.
I don’t think it’s a coincidence that SGA has looked mortal against the Nuggets compared to his standards. His True Shooting in this series is 57 percent, down from 64 percent in the regular season. Similarly, he’s posted a Usage Rate below 30 percent in every game against the Nuggets, down from his regular season average of 34 percent. At the same time, his Assist Rate has gone up. All this suggests that Denver’s zone is working as intended. It’s forcing SGA to give up the ball and challenging OKC’s secondary players to make shots.
Whenever a reporter asks an NBA coach how they’ll defend an opposing team’s best player they’ll often say something about how they plan to show him different looks. One possession, they’ll double him. Next, they’ll stunt and recover. After that, they’ll play him straight up without any help. The goal is to use a mix of coverages in hopes that it will confuse them or at least momentarily cause them to stop and think.
I think the biggest benefit the zone provide is that it forces the opposing offense to slow down and process what they’re going up against. Most teams can run a pick and roll offense against man defense in their sleep with the amount of repetitions they get in the regular season. Players see zone substantially less often so it makes sense that it would take them a beat to figure out what they need to do and how to do it. If you can make a team burn an extra couple seconds each possession because they’re busying diagnosing your defense instead of running their offense, that’s a win.
So even if it isn’t a panacea, I think we’ll continue to see more and more teams invest in zone defense going forward.
Top Ten Single Game Performances of the Playoffs
Let us not forget the fact that Jayson Tatum was playing out of his mind before he left the game with an injury during the fourth quarter of Boston’s Game 4 against the Knicks.
His 42-point performance on 72 percent True Shooting was the 7th best of the playoffs, according to Daily RAPM Estimate (DRE)
The 2024-25 MVP Race In One Chart
Before the season started, I wrote a dumb little computer script that pulled the betting odds for the MVP each day and dumped it in a Google Sheet. It was mostly an excuse to teach myself how to use GitHub Actions, but it also allowed me to create the following animated line chart.
I’m guessing the MVP will be announced sometime this week. But it’s fun to look back and see how the odds shifted over time.
Never Tell Me The Odds
These were the odds for each team/pick heading into the 2025 draft lottery.
Dallas had a 1.8 percent chance to land the #1 pick and they did it.
I think part Denver’s reason to go zone more often in game 4 and even in game 5 was b/c Jokic lack of real rim protection defence. Clogging the paint limit SGA’s ability to go off and their two bigs sometimes staying in the paint makes it tough to attack the rim so going zone some possessions works for Denver.
im curious to know their methods for identifying zone defense. some possessions must be difficult to assess. was surprised to see the zone rates so low but thinking a lot of the extreme helps/loading may not be tagged as zone.