PHILADELPHIA — It was a home run that propelled the Phillies to the World Series. It was a home run that carved out Bryce Harper’s place in the October history books. It was a home run that turned Citizens Bank Park into the world’s largest, loudest “Dancing On My Own” karaoke chorus on Sunday.

OK, all that was cool. But here’s one more thing we need to figure out about the most storybook home run of Harper’s career:

Was it “clutch”?

All right, settle down out there. I know some people are laughing harder at that question than they’ve laughed at anything since the “Curb Your Enthusiasm” season finale. I’m guessing this is what those people are thinking:

Whaaat? “Was it clutch?” The dude is the biggest star on the field, and he hit a two-run home run in the eighth inning that turned a loss into a win, and it sent his team to the World Series, and you’re asking, is it “clutch”? That’s gotta be the dumbest question ever asked.

Yes, this might seem, on the surface, like the dumbest question ever asked. But here’s the reason I asked it — because some of the smartest people I know in baseball look at the whole concept of “clutch” as the greatest baseball myth since Babe Ruth’s called shot.

“All the proclamations about clutch — they’re always after the fact.”

That’s Tom Tango talking. You should know he’s pretty much a baseball analytics legend. He’s currently a senior data architect at Major League Baseball, but that’s actually a fancy title for a guy whose job is to take complex Statcast data and use it to create a zillion fun metrics.

But that’s not all Tom Tango is. He also is someone who has been thinking and writing about “clutch” moments, “clutch” players and “clutchiness” in general for over a decade. In 2006, he co-authored “The Book: Playing the Percentages in Baseball,” one of the most important books on analytics ever written. “Clutch” was a hot topic in that book.

Just so you understand where he’s coming from, Tango wrote many years ago that “we can and should accept that ‘Clutch’ exists in some form and to some extent.” So he’s not one of those people claiming that everything that happens in baseball is completely random. But …

Does Harper’s home run in Game 5 of the NLCS on Sunday — or his incredible postseason overall — serve as the ultimate proof that he is clutch or that we all should have known that mighty blast was coming because, hey, he’s Bryce Harper? Tango is definitely not riding on that train.

“This entire argument is always after the fact,” Tango said. “And then, after the (home run), it’s like, ‘Oh, it’s obvious that this would have happened.’ Except no one — no one — would actually bet on that, right? It’s so easy to place a bet now, so if you know this and the rest of the market doesn’t, why don’t you bet on it and make a lot of money? The reality is, no one does, because it’s not real to the magnitude that you (believe) it is.”

Hmmm. Digest that for a moment because he just introduced so many levels to this clutchiness discussion, and they are really interesting to think about. So let’s think about them.

Let’s think about what “clutch” is and what it isn’t. Let’s think about it from every point of view — how players and Harper’s manager view it, how a longtime sports psychologist views it, how the analytics community views it and, of course, what the numbers say about it. I think we’ll all have fun. And if not, at least I’ll have fun.

What Harper’s teammates say

The Champagne was still dripping down Kyle Schwarber’s T-shirt on Sunday when I showed up to the spot in the Phillies’ clubhouse where he was holding court. It might have seemed like a weird time to ask if he thought “clutch” was a real thing. But I asked it anyway, after filling him in that not everyone believes it is.

SCHWARBER: “Oh, it’s a real thing. One hundred percent. Because no one can quantify a heart rate or a heartbeat. No one can quantify that. No one can quantify an atmosphere. No one can quantify who’s pitching, or the situation. You can’t quantify that. They can kiss my ass if they think that. But that’s clutch.”

So let’s take that as a yes. I also posed that question to J.T. Realmuto, because thoughtful catchers always have thoughts.

“Do you believe that clutchiness is a thing?” I asked.

REALMUTO: “Absolutely. Yes.”

“How would you describe what it is?”

REALMUTO: “It’s hard to describe, but I just think certain guys have that, I don’t know, gene, whatever you want to call it, that when they’re in a big spot, you just feel right. You feel like they’re going to come through. And obviously, it’s not always going to happen, because this is a game of failure. But there’s certain guys that, when they step into the box in a big spot, you have a lot of confidence that they’re going to come through.”

For the record, Realmuto thinks his whole team has shown this October that it’s overflowing with players who have that “gene.” Well, the Phillies have certainly located that gene over these last 11 games. I’ll say that. But let’s concentrate, for now, on Harper.

Earlier in the NLCS, I asked his hitting coach, Kevin Long, to describe that zone Harper has seemed to be in all month. Long never used the word “clutch.” But the words he did use painted that picture.

LONG: “It’s just focus, determination. It’s a different level of being locked in. I mean, it is serious. There’s no jacking around. He’s just locked in.”

I asked about Harper’s transformation to this place, from a guy who came off the injured list Aug. 26, after a fractured left thumb, and hit only .196/.288/.327 (with three homers) in his final 29 regular-season games. So how could anyone have expected this? Long said he totally expected this.

LONG: “I know Bryce, and I know he has a switch. And when he turns that switch, it clicks on.”

Finally, I asked Harper’s manager about his biggest star, just moments after they’d all climbed off the victory podium Sunday.

ROB THOMSON: “He’s just physically and mentally tough. And he wants to win as bad as anybody else in the world. And just, when the moment hits, he doesn’t get caught up in it, and he can relax, and he goes and does his job.”

I asked Thomson if that Harper home run Sunday was evidence, to him, that clutch is a real thing. He smiled.

THOMSON: “I saw a lot of years of (Derek) Jeter doing the same thing. And I think it’s not really ‘clutch.’ It’s just, their heart doesn’t speed up as much as the guy that’s throwing to him — you know what I mean? He’s just even keel. He stays in the zone.”

That’s a more nuanced view of what clutch is and isn’t — and it’s also one that is more in line with what both the analytics crowd and sports psychologists believe clutchiness is. But in general, I came away thinking there’s no bigger disconnect in baseball than the gulf between how people in uniform view “clutch” and how the Tom Tangos of the world view it.

So here’s an idea. Let’s see …

What the numbers say

Bryce Harper is having himself one spectacular postseason. There’s no argument there. But is it up there with the clutchiest postseasons of all time? Boy, is that hard to prove. But here are some numbers that at least make it look that way.

He’s crushed it with runners on base. In the 11 postseason games he’s played so far, Harper has put up one of history’s greatest slash lines with men on base:

.533/.588/1.133/1.721

Whoa. How incredible is that? In postseason history, only one player who got at least as many opportunities with runners on base as Harper (18 plate appearances) has matched or beaten that slash line over any single postseason. That would be a guy named …

Mickey Mantle! The Mick in 18 plate appearances with runners on, did this in 1960:

.571/.667/.1.286/1.953

Obviously, Harper’s postseason isn’t over, while Mantle did all that in just seven games, in an epic World Series against the Pirates. Nevertheless, that seems pretty clutch!

Win Probability Added. There’s no better measure of regular-season clutchiness than Win Probability Added, which adds up all of a player’s contributions that increased his team’s chances of winning each game. In the postseason, though, it’s not as easy to use WPA alone as a valid metric.

The sample is small. Not every player plays the same number of postseason games. And one gigantic swing of the bat — Yordan Alvarez’s Game 1 lead-flipping homer in the ALDS, for instance — can skew the WPA numbers so much that they don’t tell the full story of any player’s overall postseason.

So I decided the best way to do that was to pair players’ overall WPA for that postseason with their overall slash line. I think Alvarez explains why.

He’s hitting .241/.371/.517 in the postseason. But he accumulated more total WPA (0.91) just on that one swing than any player in postseason history has on any swing. So when I paired Harper’s WPA and overall offense, I found this:

0.878 WPA
.419/.444/.907/1.351 slash line

In postseason history, only one other player ever has matched or topped both the WPA and slash line Harper has put up in these playoffs. And that was Carlos Beltrán, in 2004:

1.046 WPA
.435/.536/1.022/1.558

Again, let’s remember that Harper’s postseason isn’t over. But have we demonstrated he’s been incredibly productive in the biggest moments so far? I think we have! But it’s time to see …

What the Sabermetrics folks think

I first started thinking of this whole concept while reading my friend Tyler Kepner’s fantastic new book, “The Grandest Stage: A History of the World Series.” He was rolling through a wonderful chapter on World Series heroes, from Reggie Jackson to Curt Schilling to Derek Jeter, when David Freese came up.

Here’s what Orioles executive Sig Mejdal, who worked for the Cardinals during Freese’s 2011 Mr. October binge, had to say in the book about Freese’s clutchiness:

“Tell me clutch before it happens; that would be great. If it’s a skill, it remains with you from year to year, and there’s been so many studies that if clutch is a thing, it’s so small it’s beyond human observation. You didn’t OBSERVE that there are clutch hitters, you FELT that there were.”

That perfectly sums up the feeling in analytics-driven front offices. If you could just tell them, in advance, everyone who was about to go on a clutch-hitting rampage — or better yet, extend that rampage through their whole career — they’d sign every one of those guys. But of course, that list doesn’t exist because, in a game built on failure, those always-clutch hitters don’t exist.

So now let’s turn back to Tom Tango, because no one has been articulating why that is longer or better than he has.

I asked if it was accurate to say that “clutch” is a thing where you know it when you see it — but you can’t predict it? Tango’s response: “I don’t even know what that means.”

TANGO: “Is that your thing, that ‘I’ve seen this fantastic moment, and therefore I’m going to start to attribute this characteristic to it’ — after the fact, that is? Is that like, ‘I don’t know what’s about to happen, but if it does happen, it’s a clutch home run? But if it doesn’t happen, it’s just a regular out?’ I mean, that’s not the way things work. You can’t describe something after the fact and then attribute it to a particular feature of it.”

He then presented this case on Harper’s home run: Let’s even acknowledge that Harper had a greater chance of hitting a home run in that spot than anyone else on the field. There is still voluminous data that tells us those odds were no better than 1-in-10.

So if the odds were stacked against him, 90 percent to 10 percent, but then he hit that home run, what did that tell us about either his clutchiness, his greatness or both? Not one thing of significance, Tango said.

TANGO: “So if, in that moment, you see someone hit a home run, what does that specifically say? The answer is nothing. It can’t possibly tell you anything, because you’re looking at one event.”

With samples that small, our minds do play tricks on us. As soon as that home run disappears into the seats, he argued, we convince ourselves that even though the odds were 90-to-10 against that happening, they must be 90-to-10 that it would happen. We’ve just seen it, so it must be evidence that this guy is so clutch that he willed it to happen.

Do we convince ourselves of these things to fit the storylines? That’s exactly what we do, he argued.

I understood his point. But I also told him: I do think that great players have the ability to do those things that make them great in big moments. He laughed.

TANGO: “Sorry. Great players do that in every moment.”

In other words, great players aren’t “clutch.” They’re just “great.” I told him about Rob Thomson’s theory on Jeter. Then I asked: “Was Derek Jeter clutch?”

TANGO: “He’s as clutch in the postseason as he was in a regular season. Because he’s Derek Jeter — and from the time he was probably 12 years old to the time he retired, he was as perfect as he’s always been. And we don’t learn anything new about Derek Jeter just because it’s April or June or October.”

But of course, great players aren’t always great in those big October moments. We talked about Clayton Kershaw and Barry Bonds and Aaron Judge, whose postseasons didn’t always give us an accurate snapshot of who they really were over their careers.

Yet if you had to choose whom you’d want pitching or hitting in the biggest moments, whom would you choose? You’d always choose the greatest players, not the supposedly clutchiest players. But even they couldn’t predict exactly what they’d do in those moments.

OK, true. But then I mentioned to Tango that, on his way up the dugout steps, Harper did say to Kevin Long: “Let’s give them something to remember.” So didn’t that say something about a player who would dare to utter those words before the fact?

TANGO: “No. Do you remember the Steve Bartman game? After Steve Bartman dropped that ball, Juan Pierre said, ‘Let’s make this guy famous.’ So is he all of a sudden Nostradamus because the Marlins did something that was practically unheard of? Or do we remember it because, after the fact, that happened? So let’s remember the things that people bet on. Let’s not talk about all the other things that people said that didn’t come to fruition.”

Our conversation went this way for half an hour. I’m pretty sure I didn’t convince him of anything. Then again, he has spent so much more time studying this than I have. But I also think there are other ways to look at the meaning of clutch. So let’s see …

What the sports psychologist thinks

The beauty of the world we live in is, we all look at that world in different ways. Tom Tango looks at events in baseball from the lane of a guy whose whole life revolves around data. And there’s no more important thing that data can reveal than what is likely to happen in the future.

But that doesn’t have to be the way we all look at the world. So do we all have to define “clutch” the way he defines it? Of course not. For a very different way to define it, I spoke with Dr. Joel Fish, director of Philadelphia’s Center for Sports Psychology, and part of the rapidly growing field of mental skills training in sports.

Fish once spent 12 years working with the Phillies. In his lifetime in this field, he has worked with numerous athletes and teams across multiple sports. So as much as he appreciates the perspective of the analytics crowd, his perspective is naturally dramatically different.

JOEL FISH: “I’m always interested in myths and facts. But I think it is a fact that there are some athletes who consistently perform better under pressure than others. And I know that sometimes statistics bear that out, and sometimes statistics may not bear that out. But I think you want Bryce Harper up there in that situation, rather than other guys who are perhaps just as talented, statistic-wise. Why? Because he has the personality traits that line up with a player being more likely to perform well under pressure.”

To become a player as talented as Harper, Fish said, “you need to be a one-in-a-million talent.” But to be a “clutch performer,” he said, “I think you need to be a one-in-a-million personality.”

FISH: “I think there are certain personality traits that increase the chances you’re going to be able to perform well in pressure situations. … And having worked with professional athletes and Olympic athletes for 25-plus years, in my opinion, the personality traits that are related to being a clutch performer are the ability not only just to embrace the moment and love the competition, but clutch performers also have less fear of failure.”

Because Fish’s world revolves around the human being, the mind and the traits it takes to succeed in those moments, he views “clutch” through a whole different lens than someone like Tango. So when Bryce Harper heads for the plate in a situation like Sunday’s, the sports psychologist knows Harper is better prepared to handle that moment than many of the players around him.

FISH: “In sports psychology, we always talk about: the bigger the game, the narrower the focus. So they’re able, really, (to succeed) in those moments where there’s 40,000 fans going crazy, and millions of people watching on TV, the World Series on the line, in a sport where somebody’s throwing the ball at you 95 to 100 miles an hour. They’re able to narrow their focus and block out those distractions in honing in on the task at hand. That’s a personality trait, in my opinion. And there’s some players that have that better than others.”

But what about the analytic world’s view, that great players have great postseason moments simply because they’re great players, not because they’re “clutch”?

FISH: “I think that not all at-bats are created equal. Not all moments are created equal. And to be up in the eighth inning at home, in his town, knowing what it means, and knowing that the whole world is watching, that’s a different moment than in April, May or June.

“In sports psychology, we’re always asking the question, ‘What are you feeling? What are you thinking? And how is it impacting your performance?’ And I’d never say to Bryce Harper, or anybody, when they go up in that moment: ‘Don’t feel nervous. Don’t feel stressed.’ Because these guys feel things. They do. And they think things. So it’s not (true that) all moments are created equal.

“The Bryce Harpers of the world have a way where, the bigger the game, the narrower their focus. They’re able to be in control of their emotions. They’re able to keep their thoughts simple. And when you do that, your natural talent is more likely to come out.”

But what, I asked, about the idea that we only see it this way after we watched this guy hit a career-defining homer, after we know that that happened?

FISH: “Look, we’re talking about Bryce Harper now because he hit the big home run. But I’d be saying the same exact things to you if he struck out, because I’ve watched this guy over a period of time. So there’s no guarantee, but clutch performers have the personality and the mental skills that increase the chances they’re going to perform better in pressure situations.”

Hey, it all makes sense – until we try to sort all of this out in our overloaded brains. So here’s my final question: What the heck are we supposed to make of The Clutch Factor when all we’re trying to do is figure out …

What just happened?

So what should we tell these people, huh? In Philadelphia, they thought they just witnessed the clutchiest home run in the history of that team they root for. Now, thanks to me and my analytics friends, they can’t be sure if it was clutchy at all.

Sorry! I never set out to confuse everybody. I just wanted to understand what “clutch” is and what it isn’t. The one thing I think we’ve learned is that it can mean different things to different people — and that’s OK. But I also wanted to know one more thing from our experts:

What would they tell these people in Philadelphia about what they should and shouldn’t take away from that home run?

JOEL FISH: “I don’t mean to sound corny here, but it’s sort of inspiring to see that, because I just think that’s what he represents with his talent, but just as importantly, as a clutch performer, with his personality. And I don’t have any crystal ball. I don’t know what’s going to happen against Houston. … But what I would say is — win, lose or draw — Bryce Harper is going to come out of that (experience) with confidence, with perspective and with hunger. … (He’s going to) want to be in that same situation next year.

“And I think, to me, that’s the hallmark of someone with a special personality. People like that — they’ve got that inner confidence, strength, a set of personality traits, that it’s not just about the results. It’s the courage to put yourself in that situation over and over and over again — because this is what we dream about.”

But in Tom Tango’s world, the advice is much more basic. Don’t overcomplicate what you saw or why you think you saw it.

TOM TANGO: “I would say just enjoy the moment.”

“I think they did,” I said.

TANGO: “And that’s all. Just enjoy the moment as it happens.”

“But don’t read any more into it?” I asked.

TANGO: “Right, because what do you think is going to happen (in the World Series)?”

I had to laugh. Then, speaking for the rest of humanity, I replied:

“I’ll get back to you in a week on that.”

(Top photo: Matt Rourke / Associated Press)