Jalen Brunson, basketball prince of the city, has to figure it out now, and not just on defense, not after we saw on Monday night what the championship-or-bust Knicks of James Dolan and Leon Rose look like when the job of the other four guys on the court is watching Brunson like they’re sitting with Ben and Timothee on Celebrity Row.

And Karl-Anthony Towns has to figure it out better than he did when it became a game-on-the-line fourth quarter for his team in Game 2; when he was being ignored by the guy with the ball, or not doing enough to demand it.

But the one who most has to figure it all out on Thursday night in Atlanta, at the beginning of what is a brand spanking new series, is the coach, Mike Brown. When it was all on the line on Monday night, Brown not having a timeout to call on the last Knicks’ possession was the least of his problems, or his team’s.

When it was over, and the Knicks had blown the 12-point lead they took into the final quarter, Brown said something about how the Knicks needed to “lockdown better.” He was right. But this was a night when he needed to coach a lot better. Because if this is a first-round series that goes wrong for the Knicks, all of their fans are going to wonder all over again what the point was in Dolan and Rose getting rid of Tom Thibodeau, the coach who put the Knicks back into the Eastern Conference finals for the first time in 25 years.

You remember how it went after they bagged Thibs, in that period when Dolan and Rose started to look like Bialystock and Bloom in “The Producers.” They didn’t just make a run at Jason Kidd as a possible replacement. They even got a turndown from the Hawks when inquiring about Hawks’ coach Quin Snyder. And from the Bulls on Billy Donovan. They finally settled on Brown, a good coach and a good guy. And now here everybody is, series tied, one-game-all.

All this time later after Thibodeau was fired, one thing hasn’t changed: The owner of the team and the president of the team — probably in that order — decided that even having watched the team having made the deepest run into the playoffs since Jeff Van Gundy was on the bench and Thibodeau was his top sergeant that the Knicks had underachieved by losing to the Pacers in the conference finals.

But what would Dolan and Rose do if the Knicks underachieve their way right out of the playoffs before they get anywhere near a possible rematch against the Celtics? Who would get blamed then?

A 7-game opening round series has now become best-of-five. If the thing somehow goes the distance — and we’re a long way from that, the sky is hardly falling because of one bad loss — three of those games would be in Atlanta. So Brown’s Knicks are now asked to come up as big on the road as Thibodeau’s Knicks against the Pistons in the first round last year.

It was another Coach Brown of the Knicks — Larry Brown — who’s always said that it’s a miss-or-make sport. And it was again on Monday night when the Knicks were missing enough shots, and enough chances to protect the ball, that they enabled CJ McCollum and the Hawks to come back on them the way they did. In the end, it was a Game 2 that felt very much like Game 1 of the conference finals against the Pacers last May.

Good grief, the Knicks didn’t lose this game because the moment was too big for them. They got outplayed, and out-coached, and finally saw all the moments when McCollum practically stalked Brunson on his way to getting another good look. Now they have a chance to make an awful lot of trouble for themselves if they don’t win Game 3, the same Game 3 they won in Detroit in the first round after losing Game 2 at home. Thibodeau’s Knicks figured it out. Now we see if Brown’s Knicks can do the same.

Somehow in Game 2, Mike Brown managed to have nearly 12 minutes of playoff basketball with Brunson and Towns sitting at the same time. Wait … what? No one would ever suggest that Brunson is Clyde Frazier or that Towns is Willis Reed. But they are the equivalent of those two on this team. How many times do you think the great Red Holzman effectively had Clyde and Capt. Willis next to him for a quarter’s worth of playoff basketball.

There was even the magical stretch when this was Brown’s five on the court: Jose Alvarado, Jordan Clarkson, Mitchell Robinson, OG Anunoby, Mikal Bridges. You know how many times that group had played together this season? For around eight minutes. They still got minutes in the fourth quarter as another Garden night was circling the drain.

“We weren’t good tonight,” Brown said afterward. “But we had opportunities where our starters were in and we were up eight to 10, and Atlanta closed it. So I wouldn’t say that specific lineup caused it.”

Well, it sure didn’t help. Now here we are. One year after being 1-1 with a young, underdog Pistons team full of scrap, the Knicks are 1-1 with a young and scrappy and underdog team coached by Quin Snyder, a team that definitely wasn’t scared of the moment — or the Garden — on Monday night. We saw how Thibodeau’s Knicks reacted to getting knocked down at home by the Pistons in Game 2, almost one year ago exactly. Now we will see how the Knicks coached by Brown — who was supposed to do better than Thibodeau — do in Atlanta on Thursday night, in the same exact circumstances. Funny how things work out. One year later, suddenly it’s second round-or-bust for the New York Knicks.