ATLANTA -- Nobody wants to be Goliath anymore. Everybody wants to be David, the scrappy, little slingshot-toting, 6½-point underdog.

Even the NFL’s ultimate Goliath, the big, bad, fee-fi-fo-fum Patriots, who are making their ninth Super Bowl appearance in the last 18 years, have spent the last few weeks trying to convince everyone that they’re The Little Engine That Could.

We’re talking about a team that, as I just mentioned, visits the Super Bowl almost as often as Donald Trump gets down to Mar-a-Lago.

They’ve been to the AFC championship game eight straight years. They’ve won the AFC East 15 of the last 16 years.

Their quarterback, Tom Brady, has a limo waiting in his driveway to take him to Canton whenever he decides to retire. Same with their head coach, Bill Belichick.

Yet, after their 13-point win over the Chargers in the divisional round of the playoffs earlier this month, there was Brady, playing the no-respect card.

“Everybody thinks we suck and can’t win any games,’’ he said with a straight face.

A little more than a week ago, after their overtime win over the Chiefs in the AFC championship game, more of the same.

“The odds were stacked against us,’’ Brady said. “It hasn’t been that way for us for a while. It certainly was this year. We fought through adversity all year.’’

Brady’s teammate and good buddy, wide receiver Julian Edelman, even has produced T-shirts with the dare “bet against us,’’ which Patriots players are expected to wear prominently here this week.

Last year, the Eagles embraced the underdog role after Carson Wentz shredded a knee in Week 14 and people started shoveling dirt on them. But they, uh, well, THEY ACTUALLY WERE UNDERDOGS.

They were three-point underdogs at home in both of their first two playoff wins over the Falcons and Vikings, and were 5½-point underdogs against the Patriots in Super Bowl LII, which they won, 41-33. So the dog masks that became all the rage in Philly weren’t a big stretch.

The Patriots? Well, they did win fewer than 12 games this year (11) for the first time since 2009. And even though they did finish fourth in the league in scoring, their points-per-game average (27.3) was the lowest since that barren ’09 season when they disgraced the New England region by not making it out of the wild-card round.

But underdogs? No respect? Seriously?

OK, they were three-point 'dogs on the road against the Chiefs. And they actually were slight Super Bowl underdogs for about a minute when the betting line first came out following the conference championship games last week. They opened as one-point ‘dogs to the Rams, but now are 2½-point favorites.

The Rams certainly aren’t taking the Patriots lightly.

You couldn’t shut up Rams coach Sean McVay on Monday when he was asked about the Patriots at Super Bowl Opening Night. He did everything but kiss Bill Belichick’s five Super Bowl rings.

Nevertheless, the Patriots are determined to spend this week believing they are the team that nobody thinks can win, or at the very least, the team that nobody wants to win. Before boarding the team charter for Atlanta, Brady got a crowd of 35,000 Patriots fans lathered up with a “we’re still here’’ chant.

Which begs the question, exactly how effective is this whole underdog/no-respect strategy?

It certainly seemed to work for the Eagles last year, and again this year when they swapped a dog mask for a ski mask after Wentz got hurt again.

“I don’t know that this would work for a lot of teams,’’ said Tony Romo, the CBS analyst and former Cowboys quarterback. “But for the Patriots, it’s been a rallying cry.

“They are a team that’s been there, done that so many times that, in some way, it’s silly to think they ever should be an underdog.

“But the more success you have, that’s why it’s so hard for teams that lose in Super Bowls, or even teams that win it, to get back. Because it’s hard to regain that same exact focus. The Patriots do it better than anybody. For them to feel slighted, it only helps them maintain that focus.’’

The beauty of being the underdog, according to sports psychologists, is that no one expects you to win, which means you’re dealing with less pressure. And less pressure often translates to better performance.

“If you’re the favorite or are supposed to win, if you win, [the result] is just a sense of relief,’’ said Scott Goldman, a clinical and performance psychologist who is embedded with two NFL teams. “But if you lose, it’s catastrophic.

“On the flip side, when you’re the underdog, not only can it be motivating because you want to prove people wrong but there’s also this element of, ‘Hey, we’ve got nothing to lose and everything to gain.’’’

Justin Anderson is the director and founder of Minneapolis-based Premier Sports Psychology. A former college quarterback, he works with professional athletes in every major sport. He said high expectations often cause even elite athletes to play a little tight.

“We know from a performance standpoint, when we play tight, we’re just a fraction of a second off in our timing,’’ he said. “That could be the difference between breaking up a play or giving up a touchdown catch. The difference is that minute.

“The way expectations tend to work in the mind are twofold. If you don’t have a lot of expectations, you don’t tend to think about the outcome or the result as much. You’re more in the moment.

“The other thing is, with higher expectations, you tend to see a lot of athletes begin to look at passive results a little bit more. Like, are we tracking the way we expected to track? And if we’re not, like, if you have a team that’s supposed to be ahead and they’re not ahead at certain parts of the game, they start to tighten up even more.

“It’s like, ‘Oh, crap. We’re supposed to be blowing this team out,’ or ‘We’re supposed to be ahead and we’re behind.’ Often times, in those case, you don’t handle the adversity as well.’’

Ask any Eagles player on last year’s Super Bowl champion team and they’ll tell you that embracing the underdog role was a big factor in helping them win the Lombardi Trophy. How much of a factor? Hard to say. But in a one-and-done atmosphere, with so much riding on every play, it helped.

And you can bet the Patriots believe it will help them Sunday when they go after their sixth Super Bowl title in 18 years.

“The negative stuff, it gives players that extra motivation,’’ said Patrick Devine, a professor of industrial, organizational and sports psychology at Kennesaw (Ga.) State University. “Even the Patriots, everybody expects them to come in and win Sunday.

“I’m sure in the locker room this week, and in that first huddle on Super Bowl Sunday, Brady is going to remind his teammates that, ‘Hey, we’ve got something to prove and we have to come out and play hard. Because people thought we wouldn’t be here. Let’s go out and show them how wrong they were.’

“I’m sure Belichick loves this whole no-respect attitude. It beats going in and saying, ‘OK, guys, we’ve won five of these [Super Bowls]. Let’s make it six. Tom needs a ring for the other hand.’

“That’s not going to get players fired up like telling them nobody thinks they can win.’’