Are the Miami Heat the future of NBA defense?

Jim Rassol-USA TODAY Sports

The Heat’s defense is great. It’s revolutionary, too.

In his 2014 novel, “Basketball Analytics: Spatial Tracking”, Stephen Shea identified rim protection as the number one variable that contributed to a team’s Defensive Rating.

Looking at the cream of the crop defensively in 2023, it appears Shea’s finding still holds true today:

NBA.com

Screenshot taken from NBA.com on January 29, 2023

The teams ranked one through four on this list all roster multiple gigantic guardians. The Cleveland Cavaliers with Jarrett Allen and Evan Mobley. The Memphis Grizzlies with Jaren Jackson Jr. and Steven Adams. The Milwaukee Bucks with Brook Lopez and Giannis Antetokounmpo. The Boston Celtics with Robert Williams III and Al Horford. And the Miami Heat with Bam Adebayo and…wait, what other big bodies do the Heat have patrolling the paint?

Interesting.

Another observation Shea made during his research was that blocks were a solid way to measure a team’s rim-protecting abilities.

Well, Miami is dead last in this category – not just among the top-5 teams, but among all teams in the NBA – averaging just 2.9 blocks per 100 possessions. Meanwhile, three of the other four teams we mentioned sit in the top eight.

So, what gives? How is this defense so good?

That’s what I was wondering for a time too, so I decided to take a look under the hood. What I found was not only the answer to my question, but maybe the template for how teams without a surplus of rim protectors can build an elite NBA defense of their own.

To start, let’s explain why protecting the rim matters so much.

Per Cleaning the Glass, the league average on all midrange shots is 43 percent (0.86 points per possession). The league average on all three-point shots is 36.4 percent (1.09 points per possession). The league average on all shots at the rim is 66.5 percent (1.33 points per possession). So, by protecting the rim, you are protecting the most efficient part of the floor.

Now that that’s out of the way, the next question becomes: how do you protect the paint?

Remember that scene from “The Usual Suspects” where Kevin Spacey says: “the greatest trick the devil played was convincing the world he didn’t exist?”

The same is true about great rim protectors/rim protecting teams. They don’t make you miss a ton of shots around the rim. They trick you into thinking that that area isn’t an option in the first place. They convince you that a shot at the rim doesn’t exist.

For instance, the Bucks, with Lopez and Antetokounmpo, allow the fourth-lowest percentage of shots around the rim (per Cleaning the Glass). They do this by keeping the twin towers near the paint to deter would-be trespassers from entering that area altogether. You can’t take shots around the rim if you can’t even get near it (unless you’re in Looney Tune Land).

Our friends in South Beach have the third-lowest opponent rim frequency, despite not touting the statuesque deterrence factors the Bucks have.

How, you ask? It’s time to meet the two faces of the Heat defense.

The first face is the Heat’s base coverage. I like to call it the Hyena Heat. As the name implies, when Miami is in this mode, they are ferocious. They are trapping/hedging, hard switching, gaping one pass away, digging/stunting at the ball, fronting in the post, and aggressively denying cutters the ball. The Hyena Heat have two main priorities: forcing turnovers (first in opponent turnover percentage) and keeping the ball in front of them (aka point-of-attack defense).

It’s hard to get shots off at the rim if the defense has two big bouncers waiting for you in the paint. But it is also hard to get shots off at the rim if you can’t get inside the three-point arc or can’t even maintain possession of the ball.

And just like Lopez and Antetokounmpo’s size are essential to Milwaukee’s success, Adebayo’s versatility is paramount to the integrity of the Hyena Heat’s shell barrier.

This isn’t breaking news or anything, but Adebayo is one of the few players in the association who can literally guard all five positions. This means that offenses can’t try to hunt him off the dribble on the switch. Not only can he hold his own against players one through five, but one could argue he is the least discriminate defender in the league. It doesn’t matter what your anatomical structure entails. When you enter Adebayo’s world, you get one heaping scoop of shutdown.

With Adebayo at the five, and their barrage of fierce perimeter guards and forwards (shoutout Haywood Highsmith), the Hyena Heat’s fortress leaves few vulnerabilities for opposing teams to exploit.

In many ways, this version of the Heat is similar to the Toronto Raptors, who also blitz and pressure adversaries in order to cajole them into turning the ball over.

Wait, the Raptors? Hasn’t their defense been getting exposed this season? How are the Heat like them?

Now, now, my friend. Read my last sentence again. I said, “this version” of the Heat. As you’ll recall from earlier, Miami’s defense wears two masks.

The reason that Hyena Heat flourishes while the Raptors desperately search for answers is that Miami has another pitch they can go to when teams are hitting their fastball. Or, like Former Coach Jeff Van Gundy said on “The Lowe Post,” they have an “alternative defense.”

That alternative defense Gundy mentioned is the Heat’s now patented zone defense. I say patented because, this year, they have become industry leaders in the field. Per InStat, Miami has run 926 zone possessions this season. The second most frequent zone advocates are the Portland Trail Blazers, who have run it a mere 365 times in 2022-23.

For most of NBA history (outside of the part where it was illegal), the zone has typically served two functions:

Acting as the basketball equivalent of a stun grenade, the zone was meant to temporarily disorient an offense long enough for a team to get back in the game/put it out of reach.
The zone also helps (for a time) weaker defensive teams mask their shortcomings in personnel by giving offenses a floor configuration they aren’t typically used to seeing.

The big issue with zone defense is that once an offense has figured it out (or “busted” the zone), many coaches find it to be more harmful than helpful. Also, many coaches fear that it teaches poor habits since it theoretically requires less ground coverage from each individual defender than standard man-to-man defense would.

I say most coaches because Miami’s Erik Spoelstra doesn’t adhere to that school of thought. He will keep toggling between the zone and Hyena Heat, even if teams appear to have solved the former.

Spoelstra understands that just because a team has vanquished the zone in one possession doesn’t mean that the same is true for every possession for the rest of the game.

People forget that players are making the decisions they make on the court in real-time, at breakneck speed. In the heat of battle, they don’t have the benefit of a broadcast view camera angle to spot the zone from, a slow motion feature to pick out the weakness in the zone, or a rewind button to see where they messed up should they fail.

They have to be able to pick out the zone from the ground level, figure out how to attack it, and execute accordingly. That is an incredibly mentally taxing endeavor, especially when the team is forcing you to do that over and over again.

Couple that with simultaneously having to worry about Miami reverting back to their more aggressive base coverage, and it’s no wonder the Heat have been able to run it so frequently, with so much success.

As for the harmful tendencies players might develop from playing too much zone, Miami’s famed “Heat Culture” pretty much negates this potential tradeoff. The grueling fitness regiment this organization requires its players to follow has likely exorcized every bit of laziness from their beings. I mean, just look at how active and attentive they look in these zone possessions:

As for the rim-protecting angle of the zone, Miami typically oscillates between a 2-3 and 1-1-3. Regardless of the alignment, both iterations of the zone enable them to have three bodies camped in the interior. Even if those bodies aren’t as menacing as the Lopez and Antetokounmpo, three bodies in the paint still present a daunting task for drivers contemplating an escapade toward the rim.

The ingredients of Miami’s top-five ranked defense consisted of one mode that focuses on building a shell around the perimeter and forcing turnovers and another that tests the limits of the opposition’s allostatic load and floods the paint with bodies.

Now, it’s worth noting that not just any team can pull this off without a hitch. You still need a switchable five-man, a bounty of turnover-inducing point-of-attack defenders, organizational-wide buy-in, and a coach that is willing to trust the process over the results.

But still, watching what Miami has done should give other teams hope that they can build a great defense too, even if they don’t have a bunch of giant shot-blockers making life easier in the middle.