HOUSTON — If the 2-3 zone that stifled the Warriors at times in the first round of the NBA playoffs looks slightly familiar to college hoops fans, there is a good reason.

The Houston Rockets have run a modified version of the defense that legendary former Syracuse coach Jim Boeheim perfected over 47 years and 1,116 victories at the hoops powerhouse.

Boeheim was not surprised that it has been as effective in the pros as it is in the college ranks.

“I think it’s good as a different look, a game changer, just to change the rhythm for teams,” Boeheim told the Bay Area News Group by phone before Sunday’s Game 7 at Toyota Center.

A countless number of coaches have used that alignment — with two perimeter defenders in front of three teammates arranged in a flat line behind — over the course of history.

But nobody is more associated with that style than Boeheim.

“It can be really effective (in the NBA) because they’re not used to seeing that, and a lot of their plays that aren’t out-of-bounds plays are man-to-man plays,” Boeheim said. “I think it’s a good move, and I think it can work, but some coaches that try it, when the team hits one shot, they get right out of it and don’t have the mentality to stick with it.”

The Rockets stuck with it, for good reason.

The Warriors were forced to trudge back to Houston for Game 7 after their 3-1 series lead evaporated. Golden State’s losses in the past two games before Sunday had many culprits, but the Rockets’ 2-3 zone was the most glaring.

When the Rockets ran out their double- and sometimes triple-big lineup with a combination of Steven Adams, Alperen Sengun and Jabari Smith Jr., the Warriors’ free-flowing offense often grounded to a halt.

Houston did not run a traditional Syracuse-style zone. Instead, it manned up on the perimeter, especially against Steph Curry, while allowing the low defenders to float.

“You can focus with your zone on Curry,” Boeheim said. “Yes, you’re going to play zone, but you’re always going to be guarding him.”

The zone’s long-standing strength is not burdening defenders with a singular off-ball responsibility. When it works well, it often leads to long possessions, which is fine with the 30-second shot clock in college but is more of an issue in the NBA game.

“Cutters don’t bother a zone that much,” Boeheim said. “It’s more about ball movement and screening. And people forget, 24 seconds is not a lot of time. A lot of teams took more than 24 seconds to score on us.”

Of course, no defense is perfect, and there were, at times, holes in the 2-3 zone for the Warriors to exploit. Getting the ball to a scorer in the mid-post is one option, and running shooters off screens is another.

“The team can try to screen for the three for the best shooter of all time, and you can’t let that happen,” Boeheim said. “You have to get over the top of it, or the forward can’t come up and he gets that shot.”

Shooting well is the classic way to break the zone, but at times during the series, the Rockets showed that the Warriors did not have the consistent snipers needed to get Houston to go back to man-to-man.

The Warriors shot 9 of 33 in non-Curry 3-point attempts in Game 6. Gary Payton II was often left wide open in the corner.

Draymond Green and Jimmy Butler are phenomenal players, but are not long-range marksmen.

“You don’t want (Curry) to get going, you want somebody else to,” Boeheim said. “Every team has one or two bad shooters, and you just don’t guard those guys.”

The Warriors know this and spent the past few days trying to devise a countermeasure to the Rockets’ defense.

But just a few hours after Game 6, Curry already knew what the Warriors needed to do against the defense that Boeheim had made famous.

“You have to resist the temptation to rush and force shots,” Curry said. “Use the attention they’re going to throw at us, whether it’s me running around or Jimmy driving it, to make the defense collapse and swing and find open looks.”

The Warriors were without Payton on Sunday as the veteran guard came down with an illness prior to Game 7. Payton had been listed as questionable before the team’s shootaround. Payton, 32, started Game 6 but was minus-12 in 20 minutes while scoring just five points and struggling to keep up with Fred VanVleet. The Rockets won the game 115-107.

Payton averaged 6.5 points and 0.8 steals per game as the team’s top defensive guard during the regular season. He had a major impact during the Warriors’ Game 3 victory, scoring 16 points as Golden State earned a 104-93 victory despite missing Jimmy Butler.