There was a time, in the not-too-distant past when a zone defense would spell disaster for the Boston Celtics. 2-3, 1-3-1, 3-2, box-and-one, it didn’t matter what type of zone was thrown at them, the Celtics just couldn’t figure a way past it. The Miami Heat know this and like to test the Celtics’ ability to penetrate their multitude of zone defenses in the hopes of stumbling across a defensive scheme that causes their offense to stagnate.
So, it was hardly a surprise when we saw the Heat filter through their defensive systems on Wednesday night, but it was certainly encouraging that the Celtics continue to find ways to push past it. Of course, having an offense predicated on continual ball and player movement is always going to lend itself toward beating a defense, but finding ways to penetrate the middle of a zone isn’t as simple as we make it sound.
Throughout their game against Miami, the Celtics leaned on three specific principles to counter Erik Spoelstra's zone defenses, each of which made a significant impact in keeping Boston’s rhythm and momentum alive. Let’s take a look at each of those principles.
By positioning a player along the free-throw line, the Celtics gave themselves an easy entry past Miami’s perimeter defense, allowing them to look for secondary creation that would spring a shooter, or cutter, free. Above, we can see that a simple entry pass to Al Horford quickly denies the first layer of Miami’s zone, as the ball gets behind them in seconds. Horford’s touch pass back out to Derrick White catches Miami’s defense off guard, as one of their primary principles is to pinch and/or dig at ball handlers when they’re hovering around the high helpline.
In fairness, Horford created that post-entry pass with the shortest of short rolls after setting a screen for Jayson Tatum. Yet, how Horford got into position is just a testament to the Celtics' overall offensive IQ, rather than a stroke of luck.
In this possession, we see the benefit of placing someone around the nail without actually looking to get the ball to them. Once Tatum positions himself around the free-throw line, Bam Adebayo is forced to step up and take away his ability to spin and drive, should a pass be made. Furthermore, you also see Max Strus look to deny the pass by digging toward Tatum, thus leaving Horford all along on the wing — which of course, is not advisable.
Similar to placing an off-ball threat around the nail, the Celtics also looked to get some secondary creation courtesy of baseline cutters, with the idea being to engage the perimeter defense with a shallow drive before finding a cutter marauding across the baseline.
In the above clip, we see that it’s Jaylen Brown who is attempting to penetrate the defense off the dribble, ensuring the focus is on him and on limiting any slot cutters who could be looking to get a free run to the bucket. As such, Derrick White finds an open lane across the baseline, and similar to Horford at the nail utilizes a touch pass to beat the defense (who now have to stop and change direction, again) to find Marcus Smart on the opposite corner waiting to get a three-point shot off.
Again, we see the Celtics look to attack Miami’s zone with a baseline cut, however, this time, they use Horford as somewhat of a decoy. By having the recently-extended big man cut across the free-throw line to set a screen for Smart, Miami’s defense is forced to react, with every member of the zone shifting toward the strong side.
As soon as Smart comes off the Horford screen, Brown begins his foray across the baseline, waiting for the defense to engage Smart’s drive and then loading up ready to receive the lob pass for an easy dunk.
Driving the gap
The thing with a zone defense is that it moves in unison, shifting side to side, focusing on what’s in front of it, which can create gaps once the ball starts to move. When you have a player with an explosive first step — a la Malcolm Brogdon, then things can start to get a little hairy for the defense.
Here, we can see Brogdon blow through Miami’s zone simply because he was able to beat their shift over toward him and attack the gap between defenders. A core principle in zone defense is not to switch, and if a man gets by you, trust the back line of defenders. Unfortunately, Brogdon is a bona fide assassin when getting his floater off, meaning this possession ended in a bucket.
Furthermore, the Celtics have become a high-level team at engaging the low-man before hitting a dump-off pass, and when looking to attack defensive gaps by driving at speed, that sort of playmaking can be quite useful.
Here's another example of engaging the low man, waiting for them to step up toward the drive, before hitting the open man around the bucket - The Celtics are eating off these when pressuring the rim. pic.twitter.com/f1eiiNkQA4— Adam Taylor (@AdamTaylorNBA) December 1, 2022
Heading into Friday’s game
Spoelstra is unquestionably one of the best coaches in the NBA, so there’s no doubt that he will be making some adjustments to how Miami looks to execute its zone defense — if they choose to utilize it all. However, it’s clear that Boston has settled on their core principles in attacking zone coverage, and given the immense scoring gravity throughout their roster, the chances of them stagnating for significant periods of time seem quite minimal.
Of course, the Celtics will have their own ideas about how they want to attack Miami, and Joe Mazzulla will certainly be making his own tweaks to the team’s system. But, for now, we can rest assured that the Celtics are more than capable of breaking down whatever zone coverage the Heat, or any other NBA team, want to throw at them.