SAN FRANCISCO >> The Warriors had a common refrain after losing Game 1 of their best-of-seven NBA Finals series.

“It’s the first one to four.”

Steve Kerr said it. Draymond Green and Klay Thompson repeated it. In the moment Thursday night, it provided comfort to a Warriors team that choked away a 12-point fourth-quarter lead on its home floor and lost 120-108 to the Boston Celtics.

But heading into Game 2 today at Chase Center, the Warriors have almost no margin for error.

Yes, if you want to be pedantic, the only true “must-win” games are elimination games, but history and the Warriors’ own words demand that we call Game 2 what it really is: A must-win game for Golden State.

If the Warriors don’t win Game 2, the truth is that their chances of winning those requisite four games in this series drop significantly, if they are not altogether eliminated.

No team in the history of the NBA Finals has ever come back to win the title after losing the first two games of the series at home.

In fact, in the entire history of the seven-game NBA playoff series, such a turnaround has only been accomplished four times. And then, it only happened in the first and second rounds.

Fail to protect home court in the first two games of the series, and you’re looking at the prospect of needing to win four of the next five games, with only two of those contests coming at home.

Even for the Warriors, with all of their enviable playoff experience, to accomplish such a turnaround seems far-fetched.

The Warriors have experience coming out of their ears, but they haven’t danced with a predicament like this often.

In fact, Thursday’s Game 1 marked only the third time in 24 playoff series under Kerr that the Warriors have lost.

One came in the NBA Finals (2019), and one came at home (2016 Western Conference Finals).

Both times the Warriors won Game 2. The Warriors can take solace in that.

But Golden State will need to come back from 1-0 a third time today if they want to raise a fourth championship banner.

“They have seen it all,” Kerr said of his team’s veterans. “They have won championships. They have lost championships. They have had their heart broken. They have had parades. This is all part of it.”

For the younger players, Warriors star Steph Curry sees lessons in this team’s peculiar playoff path, which has seen it fail to close out three times in three series.

“I look at how we responded from Game 5 to Game 6 in the Memphis series; Game 4 to 5 in the Dallas series. Even moments throughout the regular season where things are starting to get away from us a little bit at times and kind of have your come-to-Jesus moment, like we need to play right. We usually responded pretty well,” Curry said Saturday, with a caveat. “It’s the first time for a lot of things with this particular group. We are here in the Finals for a reason, because we figured it out along the way. If we’re going to get back in this series, we’ve got to figure it out again.”

Is this is a “come-to-Jesus” moment for the Dubs?

“Absolutely,” he said.

Getting Jesus involved? The devout Curry wouldn’t do that unless it was a must-win game, right?

The Warriors are also taking some solace in how Game 1 was lost.

The Warriors’ 12-point lead was no fluke. The loss was characterized by the Warriors taking their foot off the pedal and Boston taking advantage of the lull.

And amid that characterization, another word was dropped a few times: Desperation.

“We have to come out with a sense of desperation in the first quarter and really cement ourselves in terms of what we are trying to do,” Curry said. “Play with the same joy, the same aggressiveness that we always do, but have to sustain it over 48 [minutes]. It’s crazy saying that. That’s what it should be like in the Finals with two great teams going at it.”

Thompson said all-out effort is needed.

“We played about 40 great minutes, which will not get it done at this point in the season,” he said Saturday. “It was a harsh reminder, but something we all needed to go through, including myself. It’s about how we respond tomorrow, which I am very excited for. We are going to play with desperation ... and I think that’s when we are at our best.”

If I didn’t know any better, I’d say that desperation is something you bring to a must-win game.

Otherwise, what a waste, right?

Yes, Game 1 could serve as a wake-up call for the Dubs at the start of what could be a classic Finals series. Or it could be a precursor of a Celtics coronation.

It’s on the Warriors to determine which way it will go, and you can bet the Celtics won’t be complacent with one win to start the series.

And with outcomes so different, Game 2 is absolutely, 100% a must-win game for the Warriors.

Don’t let anyone else tell you otherwise.