Just how good has the Miami Heat’s defense been early this season? Here’s a closer look

Just how good has the Miami Heat’s defense been to begin the season?

The Heat has posted a defensive rating of 91 points allowed per 100 possessions or better in three of the first four games. The Heat pulled that off just once in 72 games last regular season.

Takeaways and details from a dominant performance from the Heat’s defense against the Nets

The Heat limited the Brooklyn Nets to a season-low offensive rating of 90.3 points scored per 100 possessions in Wednesday’s impressive 106-93 win at Barclays Center, with Kevin Durant and James Harden both playing in the contest.. Brooklyn finished with a worse single-game offensive rating only once last regular season, and the superstar trio of Durant, Harden and Kyrie Irving did not play in that game.

The Heat entered Thursday with the NBA’s top defensive rating (92 points allowed per 100 possessions) and has held opponents to a league-low in field goal percentage (39.2 percent) for the season.

The Heat has already won two games this season despite shooting worse than 28 percent on threes. The Heat finished 0-17 in such games during the past two regular seasons.

“It feels good to be able to win games knowing that you’re not making shots,” Jimmy Butler said, with the 3-1 Heat returning home to face the Charlotte Hornets (4-1) on Friday (7:30 p.m., Bally Sports Sun, ESPN). “I feel like we have a group that prides themselves on getting stops. Everything is not going to be all good every single night. But when you do got dogs, they’re always going to find a way to win and we got a couple of them that just love to go out there and play bully ball.”

The Heat’s defensive success isn’t too surprising, considering its revamped roster profiled as an elite defensive team following the additions of six-time All-Star Kyle Lowry and veteran forwards P.J. Tucker and Markieff Morris.

Miami has not wasted any time incorporating those new players into its defensive system to put together dominant performances on that end of the court early in the season. The quartet of Bam Adebayo, Butler, Lowry and Tucker has posted an absurdly good defensive rating of 84.2 points allowed per 100 possessions in the 45 minutes they have been on the court together this season.

“I can be on KD and Bam will switch, and I’m like cool,” Tucker said. “Jimmy will switch, I’m like cool. Kyle will switch, it’s like cool. We’re not tripping. I know what those guys are going to do. They’re going to play hard, they’re going to give everything they got. Whether they score or not, do it again the next possession and we can talk to each other. Bam can say whatever to me, I can say whatever to him and then we can yell at each other, and then go out there and we’re going to play and it’s done. To have that kind of chemistry with guys this early in the season, it’s nice.”

While some of the personnel is different, it doesn’t seem like the Heat’s defensive philosophy has changed much since finishing last regular season with the NBA’s 10th-best defensive rating.

Miami’s switch-heavy system is set up to close driving lanes and limit opportunities around the rim even if it means allowing an opponent to shoot a bunch of threes., which resulted in the Heat allowing a league-high 40 three-point attempts per 100 possessions last season. The Heat entered Thursday allowing the third-most three-point attempts per 100 possessions this season at 40.6.

“It was similar last year, as well,” coach Erik Spoelstra said when asked about those numbers. “I’ll be honest, we haven’t totally wrapped our mind around it. We’re working on it. I don’t love giving up that many threes.”

It helps that opponents are shooting just 28.6 percent on threes against the Heat this season, but that’s probably not sustainable considering only one team has finished the regular season with an opponent three-point percentage worse than 31 percent since 2010 (the Boston Celtics in 2011-12).

“It makes the head coach extremely uncomfortable when those are launching up there,” Spoelstra said. “But a lot of the other things that we do are grading out pretty good. It’s still too early and the sample size is too small. We’ll just have to see how that plays out.”

What can’t be denied, though, is the improved personnel that the Heat has to execute its defensive game plan. The additions of Lowry and Tucker to a starting group that already included Adebayo and Butler has seemingly elevated Miami from a good defensive team to an elite defensive team.

Players are shooting just 29.3 percent this season when defended by Tucker, which is 16.5 percent worse than their usual combined shooting percentage, according to NBA tracking stats. Tucker spent most of Wednesday’s game guarding Durant, who scored just six points on 2-of-6 shooting and committed four turnovers on possessions he was defended by Tucker.

“I think the biggest quality that P.J. has is that relentless competitiveness,” Spoelstra said. “So, yes, clearly you see the physicality and his strength. But he’s extremely detailed, so he knows scouting reports, he knows tendencies. He has obviously played against Durant many times. But I think the most important quality is he doesn’t get discouraged. ... P.J. will just keep on coming after it.”

The Heat is also closing more defensive possessions with rebounds this season, as it owns the NBA’s top defensive rebounding percentage (the percentage of available defensive rebounds a team grabs) at 81.4 percent after finishing last regular season with the 19th-best defensive rebounding percentage at 73.3 percent.

Because of Miami’s improved rebounding early this season, opponents have scored an NBA-low 6.6 percent of their points against the Heat off second-chance points compared to 11.4 percent last season. Those second-chance opportunities that Miami has eliminated make a difference.

“I mean, we’re just flying around and just trying to get the job done,” Adebayo said. “We’ve got a lot of guys that just want to win at the end of the day, and they’ll do anything to get that win — diving out of bounds, diving for a loose ball, getting on the floor. And we’re doing it together, and as a collective unit, and it’s paying off for us.”

But maybe the most encouraging aspect of the Heat’s early season defensive success is that it believes it can be a lot better.

“I think we’re OK right now,” Tucker said when asked about the Heat’s switching on defense. “We’re not great. It’s not great, trust me. It’s not perfect. But the thing with switching is even when you mess up, it’s having each other’s back. And when you’re rotating and communicating, there are so many more things that go into it. You’re going to mess up. But it’s the effort and the energy, and we do that. That’s the key to it. I think that’s a huge key to it and it’s the reason why our defense has looked pretty solid so far.

“Has it been good? Debatable. But we play hard, so I think we’re going to get better and better as the season goes on.”

▪ Adebayo (left knee bruise) and Lowry (right elbow bursitis) are both listed as probable for Friday’s game against the Hornets.

Marcus Garrett (G League assignment) and Victor Oladipo (right knee injury recovery) remain out.