The Knicks went back to old reliable.

And it sparked their historic Game 1 comeback.

There has been so much written and said about the offensive transformation that was behind the Knicks turning a 2-1 first-round deficit into seven straight overpowering wins.

They began playing through Karl-Anthony Towns as a facilitator from the elbows, allowing others around him — notably Jalen Brunson — to cut and set screens around him. The Hawks and 76ers had no answers. Towns’ assist numbers skyrocketed.

But predictably, it was not nearly as effective against the Cavaliers and their two strong big man defenders in Evan Mobley and Jarrett Allen. Towns’ ability to easily see and pass over Onyeka Okongwu and Joel Embiid was key to that system thriving. Mobley and Allen, though, are much more active and disruptive defenders and made it much more difficult for Towns to facilitate.

He had seven turnovers compared to five assists.

So down the stretch, as the Knicks mounted their epic comeback, they went away from that system. It was back to having the ball in Brunson’s hands to start possessions, with the others spreading the floor and letting him score in isolation. And he took over.

“That’s just the action we went to at the time,” coach Mike Brown said after practice Wednesday. “But we have a lot of other stuff and we didn’t execute well throughout the course of the game. We have to do a better job of it. And we tried to clean a lot of it up today and hopefully it will translate to the game [Thursday] because I feel like everybody we have on the floor is dynamic, our offense has been dynamic and we don’t want to lose sight of that.”

Brunson scored 15 points in the fourth quarter, including 11 straight Knicks points. Possession after possession, he relentlessly hunted James Harden. If Harden wasn’t initially on Brunson, the Knicks got him involved in an action, and he repeatedly switched way too easily and ended up on Brunson.

The Knicks forced Harden to switch onto Brunson for nine isolation plays in the fourth quarter and overtime, according to the “All NBA Podcast,” which features ESPN’s top NBA analyst Tim Legler. They averaged an incredible 1.9 points per action. Cavaliers coach Kenny Atkinson curiously watched it all unfold for a long stretch before calling timeout or adjusting to have Harden avoid guarding Brunson.

“It was cool,” Josh Hart said Wednesday. “Obviously he took over the fourth quarter, overtime.”

This wasn’t the free-flowing offense with ample ball movement that was on display across those seven games. This was mano a mano, with Brunson embarrassing Harden.

That doesn’t mean the Knicks have to completely abandon the Towns-centric system, though. It struggled in Game 1, and the Brunson ball-dominant system proved to be the more effective for that situation.

But it now provides the Knicks with different systems they can utilize in different scenarios.

The Knicks are confident that they will be able to revamp the Towns-centric system, particularly as the series goes on. OG Anunoby, whose cutting around Towns is pivotal to that system, getting more and more healthy should help.

“Trying to show the diversity our group has,” Brown said. “Not just with the actions that we try to execute but with the players involved in it. I have to try to do a better job of helping with that diversity throughout the course of the game so that down the stretch we have a few more things that we go to.”

The Knicks also expect the Cavaliers to adjust, even if Atkinson doubled down Wednesday on his support of Harden as a one-on-one defender. If the Cavaliers try to blitz or double-team Brunson, it would make sense for the Knicks to revert to the Towns-centric system.

“They are going to be ready and mix it up at the end of the day,” Brown said. “It’s our job to make sure we are more efficient and we are more diverse offensively so that no one can sit on any one action we are trying to run.”

It became clear that Brunson hunting Harden is where the Knicks likely have their biggest advantage. The Cavaliers lack any sort of defensive ace that can slow Brunson down when he’s in a rhythm.

But they still have their recent revelation in their back pocket.