Kyle Ross-Imagn Images

PHILADELPHIA — “What could Jac Caglianone possibly have done to these people?” I thought to myself on Monday night. The young Kansas City Royals slugger has scarcely been in the majors a year; he’s played the Phillies only six times and not accomplished much. Surely Phillies fans didn’t have a consensus view — good or bad — on his college career at the University of Florida. If there is a historical grudge against the Royals, it’s faded to nothingness 46 years after the two teams met in the World Series.

And yet he was getting booed. I didn’t understand it. Surely Philadelphia would be predisposed to love this up-and-coming Italian-American slugger with 80-grade power and an inoffensive home market. Not all of the 43,000 sweat-drenched unfortunates in attendance were Phillies fans — enough Orioles diehards had made the trip up from Baltimore to make their customary National Anthem shout audible throughout the park — but the majority of the onlookers were locals.

And they were letting Caglianone have it.

Then Jordan Walker ducked through the arch to have Michael Buffer call his name, and the fans’ opprobrium continued. Instantly, it was clear: Hometown heroes Kyle Schwarber and Bryce Harper were in the Home Run Derby field, and everyone else was going to get jeered mercilessly.

Yankees first baseman Ben Rice got the worst of it, and while the intensity of the booing surprised him, he didn’t come in expecting a hero’s welcome. “That’s just the price of the pinstripes, I guess,” he said.

Once Rice realized that the crowd had cast him as a heel, he quickly adapted to the role.

“You’ve got no choice but to embrace it,” he said. “You wouldn’t want it any other way. It was super fun, especially in the opening ceremony, just walking out and hearing how loud the boos were. It was cool.”

Red Sox first baseman Willson Contreras got an earful during his introduction — Philadelphia’s relationship with Boston sports isn’t exactly defined by a harmonious mutual affection for Shane Victorino — and he went even further than Rice. He egged the crowd on, cupping both hands behind his ears as he stepped to the plate to face Schwarber in the semifinal. In return, the fans cheered loudly whenever Contreras took a swing and failed to hit the ball out.

It wasn’t the first or last time Philadelphia fans lived up to their reputation. At the draft on Saturday, the crowd at the Pennsylvania Convention Center booed their intradivisional rivals’ mascots and draft picks, as well as a guy in a Nationals jersey who was pulled from the crowd to answer trivia questions for Home Run Derby tickets.

I mentioned this in my writeup of the draft, but the anecdote bears repeating: Over a chorus of boos, Commissioner Rob Manfred announced that the Braves had taken Carter Beck 26th overall. Manfred, usually not the avatar of levity, started laughing when he read his next line: “The New York Mets are on the clock.” The crowd, who’d gathered in a dark room on a Saturday to hear names read off a list, suddenly found a new level of disapproval.

On Monday, the crowd booed not only Rice and Contreras but eventual champion Jordan Walker, who reeled off an astonishing three straight do-or-die homers to best Schwarber. They booed one of the kids shagging balls in the outfield when he came up short on a Walker pop-fly. (The kid, a 17-year-old from nearby Lower Merion, told Alex Coffey of the Philadelphia Inquirer: “I loved that. I think it’s an honor, to be honest.”)

In the muggy Tuesday twilight, as Major League Baseball paraded its best and brightest before the South Philadelphia multitudes, Billy the Marlin and Blooper got it again. Mr. and Mrs. Met, absent at the draft, got booed twice as much. Maybe because there were two of them.

Come player introductions, local products Mike Trout and Kevin McGonigle received uproarious cheers, but divisional rivals and recent playoff foes (Astros and Dodgers especially) got the business.

“It’s Philly. The fans out there are electric. They love their team, and you know it’s all fun,” Nationals shortstop CJ Abrams told me before Tuesday’s game. “When you’re playing baseball, you’re competing, so the fans feel like they’re competing with their team.”

Four hours later, Abrams got an earful as he came out to sign the Declaration of Independence-shaped lineup card. It didn’t seem to bother him much.

Cardinals reliever and first-time All-Star Riley O’Brien enjoyed the Home Run Derby environment.

“[It surprised me] a little bit,” he said. “But to me, it seemed like it was all good fun. The hitters were embracing it, and the fans seemed like they were having a good time.”

The Home Run Derby and All-Star Game are usually feel-good, essentially nonpartisan events. Polite cheers are the norm, with certain exceptions. For instance, the last time the All-Star Game was in Philadelphia, in 1996, Joe Carter received quite a hostile reception. Turns out, if you hit a walk-off home run to win the World Series, the fans of the team you did it to will tend to hold a grudge.

But Philadelphia sports fans — of which I’ve counted myself a member since I was old enough to count, period — pride ourselves on being noisy and hard to please. Last October, there was a minor kerfuffle when Shohei Ohtani, the saintlike and studiously noncontroversial face of baseball, got booed at Citizens Bank Park during the NLDS. But no iconic figure is immune.

Sixers fans booed Beyoncé during the 2001 NBA Finals, and she deserved it. Eagles fans famously threw snowballs at Santa Claus, which sounds like psychopathic behavior until you hear the whole story, which makes it clear that ol’ Père Noël got off easy.

So while the booing was somewhat controversial in some circles, there’s a cultural element at play here. I remember podcasting with Ben Lindbergh years ago, and he was scandalized that fans of a team (I don’t remember which, but it wasn’t the Phillies) were booing their own players. He asked what I thought, and I said, “Dude, where do you think I’m from?”

When I was in college, I called home during the 2008 NLCS, which pitted the Phillies against the Dodgers. My dad, who is not from the Philadelphia area, was amused that Dodgers fans chanted “Let’s go Dodgers,” while Phillies fans chanted, “Beat L.A.!”

I remember not really getting the distinction. Baseball being a zero-sum game, rooting for the opponent to lose is the same as rooting for your team to win. When it’s an eight-way competition with six visiting competitors, or when Braves, Mets, and Phillies are all on the same team, it gets weird. But that’s what makes the All-Star Game special.

In some places, booing might be the pinnacle of fan hostility, but in Philadelphia, it’s just business. Like Abrams said: It’s the fans’ way of participating in the competition. Just like you cheer to express excitement, you boo to express displeasure. The players are meant to hear it, and respond to it, but it’s not personal. There are definitely things fans can — and, unfortunately, do — say to players that cross the line into the hurtful and personal. Which is why the boo, with its round, blunt edges, is so useful.

The question of why Philadelphia fans are like this has been oft-discussed and, if anything, overreported. I think there’s a lot of truth to the fact that the famous Philadelphia chip-on-the-shoulder is born from insecurity over the importance of nearby Washington D.C. and New York. Or the recent sporting successes of Pittsburgh and Boston. Badger a Philadelphian long enough and you’ll probably get them to admit that New York, if only because of its size, can claim a certain cultural cachet. But there’s no way in hell Boston is better than us.

This is also a tremendously insular city, and region. Families settle in a neighborhood and stay there for hundreds of years.

The weather absolutely sucks, as anyone who was in town for this All-Star Game knows. And unlike Minneapolis or Houston, where it sucks for half the year but is pretty nice when the Earth’s axis is pointed the right direction, Philadelphia gets a little bit of everything. Searing, swampy heat. Blistering cold. My personal bête noire is the sleety period of late fall, which is damp and frigid and miserable, and soaks through your clothes to chill in ways even a polar vortex can’t match.

In short, people around here can get a little tetchy.

But they’re also ferociously protective of their own, and anyone who plays hard and well can become a favorite son, no matter where they come from. Most Phillies would rob a bank if Schwarber or Cristopher Sánchez demanded it. And whatever you might say about Harper, he instantly understood what he had to say and do in order to earn cult hero status.

Interlopers from New York or Boston turned out not to be popular when they stood in Schwarber and Harper’s way. Also, let’s not act like Philadelphia invented booing during the Home Run Derby.

“Anything you can do to get your hometown guy to win,” Rice said of the boos. “Nothing you can do but embrace it and enjoy it. Because, you know, we’re putting on a show.”

It’s worth remembering that last point, because — bear with me here — sports are improvised dramatic theater. We have characters, high stakes, rising tension, climactic action, catharsis, the whole shebang. Now, in modern theater it’s considered impolite to hoot and holler when Mark Antony turns the Roman public against Brutus, but that wasn’t necessarily so when Shakespeare wrote Julius Caesar.

In fact, the history of Western theater is full of traditions in which the audience is meant to react to heroes and villains audibly. At least, that’s the point I thought I was making as I excitedly told Rangers reliever Jacob Latz, “This goes back to the ancient Greeks!”

Latz, bless him, seemed to understand the idea well enough.

“I think it’s really cool. It’s all for the competition, for the game, right?” Latz said. “When the crowd’s into it, it allows us to raise our game to another level. I think that’s something we all feed off as players, and it helps you build the competitive nature of it.”

Latz has relevant recent experience with rowdy fans. I’m sure you remember the wildly popular invaders from Scotland during the World Cup. The Tartan Army descended on two MLB games en masse, one in Boston, the other in Miami. By happenstance, Latz’s Rangers were the visiting team both times.

“We had a taste of it in Boston and Miami,” Latz said. “The Scotland fans found a way to do chants, boo, cheer without getting disrespectful. It was really cool for us as Americans to witness.”

The baseball diamond is a stage, but so, Shakespeare wrote, is all the world. Some people were destined to pitch or hit. Others to cheer, or sing. Or boo.