The Rockets shoot very deep 3-pointers on purpose. Here’s why.

BROOKLYN — In a league where the three-point shot is on an upward trajectory, the Houston Rockets are somehow ahead of the curve.

The Rockets attempt a league-leading 40 three-pointers per game and make 15 of them, ahead of the Cavaliers (12.6), Celtics (12.0), and Warriors (11.8). Houston’s made almost 160 more triples than Golden State and has attempted 500 more threes than the Los Angeles Clippers.

But there’s a new wrinkle in the Rockets’ three-point prowess: the distance from which they shoot them.

The NBA three-point line is 23 feet, nine inches from the basket, yet more than half of Houston’s three-point attempts come from between 25 and 29 feet. They don’t just shoot a lot of threes. They shoot a lot of deep threes.

And that leads to a lot of facepalms from opposing coaches.

“It’s different from reading it on the scouting report and seeing it on the tape [vs.] seeing guys pull from two, three feet behind the line,” Nets coach Kenny Atkinson said after Houston nailed 21 threes in its 137-112 win over Brooklyn Jan. 15. “You know, I see the stats, too. I read the articles. I know that’s kind of what they do. So, [it’s] tough to defend.”

James Harden wasn’t surprised Ryan Anderson and Eric Gordon could launch three-point bombs from as far out as they do.

“No. Nuh-uh,” Harden chuckled during Houston’s January shootaround in Brooklyn. “Just happy they’re on my team.”

The Rockets’ sharpshooters are happy to be in Houston, too. Gordon ranks second in the NBA in three-point makes (153), just three shy of Stephen Curry. He, Harden, Anderson, and Trevor Ariza each rank in the league’s top seven in threes made. Combined, they account for 81 percent of Houston’s three-pointers and have made more triples (530) than every other NBA team.

But the idea to spread the shooters further out wasn’t something Rockets head coach Mike D’Antoni forced upon his players. It’s something that just happened within the flow of the game.

“You look at ‘em and you go, ‘Yeah, why not?’ It’s easy,” D’Antoni laughed. “You can see on their form and effort, it’s just an easy shot for them. So, there’s no difference from them standing on the line.”

Gordon leads the NBA with 114 three-pointers made between 25 and 29 feet, per NBA.com stats. The only players to make at least 55 of them and shoot a better percentage are Toronto’s Kyle Lowry and Charlotte’s Kemba Walker.

“I know how far I am, sometimes,” Gordon conceded after pelting the Nets for 24 points on 4-for-8 three-point shooting. “You know, it’s all about creating a good shot at the end of the day. And if I’m making ‘em, I’m just gonna continue to keep shooting it.”

Harden isn’t too far behind, having nailed 92, and Anderson is next up with 73 deep triples. Along with Curry, Harden, Anderson, and Gordon hoist three of the four most attempts in the league from that range.

“Especially as the game changes and defenses change, it’s more difficult to get open looks,” Anderson told SB Nation. “So, naturally I think you just obviously go farther and farther back when you get an open look.”

Many teams employ the spread offense. Brooklyn does it and executes well, but the Nets shoot just 33.6 percent on 33 three-point attempts per game. Cleveland, Golden State, and Boston each make a living on the perimeter, too.

But by moving farther back, Houston’s shooters are stretching opposing defenses even further than other good perimeter shooting teams. In fact, it forces them to make a decision: Defend a very deep three-ball, or defend an all-world scorer.

“You know, actually it gives the shooter a little bit of an advantage because they just can’t get back,” D’Antoni said. “Most teams are gonna load up on James [Harden] anyway. If they’re off him, then that’s their problem.”

Both Anderson and Gordon are marksmen from distance. Defenders certainly can’t leave them to help on Harden; if they do, he almost always makes the right pass. Therein lies the conundrum Houston’s stretch offense poses opposing defenses.

Most NBA coaches wouldn’t dare embrace players chucking up shots from three, four, and sometimes five feet behind the line. But D’Antoni is cut from a different cloth. He proved that when he pushed the boundaries of the three-point shot in the mid-2000s with his Steve Nash-led Phoenix team that led the league in triples for years.

And he’s back at it again, pushing those same boundaries a step further, so to speak.

“The line is there,” D’Antoni said. “Doesn’t mean you have to stand on it.”