The Knicks (37-19) own their best post-All-Star break record in decades. But that doesn’t mean they are legitimate title contenders — until proven otherwise.

On Friday, they endured a 37-point loss to the Cavaliers, the largest defeat under head coach Tom Thibodeau, per ESPN Stats & Info. The loss also marked the third-largest in Thibodeau’s head coaching career.

More glaringly, the loss meant that the Knicks are now 0-6 against the Celtics, Cavaliers and Thunder — the three best teams in the league. The Knicks were blown out by at least 27 points in four of those losses, proving they’re not up to snuff with the elite teams.

It’s not just the powerhouses the Knicks have struggled to beat. Thibodeau’s team is now 11-13 against teams above .500, giving up 116.9 points per game against winning squads.

Their 37-19 record, good enough for the third seed in the East, has been built upon their 25-6 record against teams under .500. These metrics scream pretender, not contender.

Thibodeau has urged his teammates to put the blowout losses in the rearview mirror and look to the future.

“Just can’t give in, and that’s the biggest thing,” Thibodeau said after Friday’s loss, via ESPN. “You can’t allow anything to break you.

You got to have the mental toughness to get through things. And so, there’s got to be a lot more resolve, particularly on the road against the team that is this good, you know?”

The Knicks will get another chance to prove they’re not pretenders when they face the Celtics on Sunday.

They lost handily to the champs in both previous clashes, including a 27-point drubbing earlier this month. Another blowout loss could be devastating to team morale.