After the new year, when the Sixers really started rolling, Brett Brown began noticing certain things on road trips. During a timeout or a slow moment in the game, he’d take note of “this pocket of empty hundred seats or that pocket of empty hundred seats” in opposing arenas. When Brown first started coaching the team, the Sixers had the same bald spots in their gym. Lots of them. One fan famously bought an entire row of tickets for less than a dollar.

The NBA Playoffs Check out The Ringer’s coverage of the 2018 NBA playoffs

But that was five years ago, which feels more like 50 when you consider how far these Sixers have come. They entered the playoffs on a 16-game winning streak, and they went 23-2 at home between Christmas and the end of the regular season. They don’t have problems filling seats anymore, and the Wells Fargo Center, which used to be uncomfortably quiet during the lean years, is now so loud that I had to scream to talk to the reporter seated next to me in the press box—and that was before the Sixers tipped off their first playoff game in six very long seasons on Saturday night against the Miami Heat.

That’s exactly what Brown said he wanted and expected: “volume.” More than once on Saturday, Brown mentioned playing the Warriors at Oracle Arena and how loud it is there. When he interviewed for the Sixers head coaching job in 2013, that was part of the potential appeal—a place he thought could eventually offer a similar atmosphere. He remembered coming to Philadelphia when he was still an assistant with the San Antonio Spurs back “in the Allen Iverson days.” Those were the days when all it took for the Philly crowd to lose its shit was Iverson cupping his hand to his ear. That’s what he thought the Sixers could get back to one day. But even when he was “dreaming out, projecting what it could be,” he didn’t think it would get quite this crazy.

“This is a legitimately loud gym,” Brown said. “This place is going to blow up tonight.”

He wasn’t wrong. From the prerequisite “Trust the Process” chants, to Joel Embiid materializing in a Phantom of the Opera mask to ring the opening bell, to the final buzzer, the crowd didn’t shut up—not even when the Heat went on a run and built a 12-point first-half lead that threatened to spoil everyone’s good time. The faithful even got in a few Eagles chants for good measure along the way. Because, Philly.

The Sixers beat the Heat, 130-103, and went up 1-0 in their first-round series. It was a big game for the team and an even bigger moment for the city. It was what Process loyalists always expected and detractors never dreamed possible: successful playoff basketball courtesy of a host of homegrown talent. It served as a long-awaited, massive energy release. At one point right before halftime, I watched a kid chant “Let’s go Sixers” so many times, and so hard, that his face turned the same shade of the red Ben Simmons jersey he was wearing. He was maybe 10 or 12—a perfect, pint-sized representation of the area maniacs that I grew up among and think of fondly precisely because of their special strain of shared genetic hysteria.

“That is a Philly edge that we want,” Brown said about the atmosphere. “There is a gratitude that I have, we have, that finally, here we are.”

In the run-up to the game, there was some debate about how Philly’s style would translate to the playoffs. The Sixers were second in the league in assist percentage and fourth in net rating and pace during the regular season, according to NBA.com. They play fast, and they play excellent defense—they were third in defensive rating, and only Utah and Brooklyn forced more midrange shots, per Cleaning the Glass—which is precisely the kind of formula that helped them win more than 50 games for the first time since 2001. But the playoffs can be tricky, and things that work in the regular season don’t always go so smoothly in the postseason.

With Embiid out, maybe the biggest question was about Simmons and whether anyone could stop him. He was fewer than two rebounds and two assists per game shy of averaging a triple-double for the regular season, but the issues with his shot are well documented. He hit just 56 percent from the line and did not attempt a regular 3-pointer all season. The 6-foot-10 Rookie of the Year hopeful carried the Sixers down the stretch without Embiid, but the expectation was that Heat head coach Erik Spoelstra would have his guys sag way off Simmons in an attempt to keep him out of the paint, where he does most of his damage (558 of his 998 field goal attempts were either dunks or layups, per NBA.com). That’s pretty much how most teams played Simmons this year. That’s how the Heat played him, too. But as was the case for most teams in the regular season, giving Simmons all that space didn’t work the way Miami would have liked in Game 1.

So much for the plan to stop him. “The game has to be on our terms,” Spoelstra said after the loss. Maybe the next one will be, but the first most certainly wasn’t. Simmons nearly had another triple-double: 17 points, 14 assists, and nine rebounds. He added two steals for good measure.

Sure, he went 5-of-13 from the field, but it hardly mattered. Even when the Heat pressed him, he found ways to create.

At practice at the Sixers’ training facility in Camden, New Jersey, on the day before Game 1, Ringer podcaster J.J. Redick, who moonlights as a Sixers shooting guard in his free time, said that not having any playoff experience might actually be a good thing for his teammates, many of whom had seen the playoffs only on TV before Saturday evening. He said they just didn’t “know any better,” which he saw as a weird edge. “Like, with Ben, I think that’s an advantage for him. His demeanor will be a calming presence for our team.”

That demeanor is what Brown called, in a way only he could, “un-sort-of-flappable.” When Simmons was asked the other day how excited he was for the playoffs to begin and whether he could put it into words, he responded, “I’m ready to go, I’m ready to play,” in a soft monotone that made Redick, who was standing next to him, fight back a smirk. Even after beating the Heat, Simmons stayed, as he put it, “locked in.” When a reporter rattled off his stats and wondered what Simmons thought of his first playoff experience, the rookie responded the way we probably should have expected: “I’m ready to play the next game.”

But while Simmons’s default position is cool and uncrackable, there are moments that demand emotion. In the third quarter, while the Sixers were starting to pull away from the Heat, Simmons victimized poor Kelly Olynyk, who had the misfortune of trying to guard him. Simmons turned him around, then blew past Olynyk for a ferocious dunk. When he let go of the rim, Simmons flexed in midair and roared as he landed.

That’s the kind of evening it was in South Philly. Even Simmons couldn’t help but scream.

Right before his guys got the first exam that actually matters, Brown called the NBA playoffs “the greatest professor you’ve ever had.” He told his players, especially the young ones without any postseason experience, that “each of you are going to learn more about yourselves than any coach or any experience could have taught you ever.”

It was only one game, but what we learned about the Sixers was a continuation of the lesson they’ve been teaching the league for the last 17 games. Redick, who is a pretty good basketball player for a podcaster, had a game-high 28 points as part of one of the most efficient 3-point performances by a team in NBA history. Marco Belinelli had 25. Dario Saric had 20. Robert Covington scored only nine, but he played customarily terrific defense and blocked three shots. (“I thought he was unbelievable,” Brown said about RoCo’s defense. “I thought he was a man.”) Things went so well that Markelle Fultz got on the floor for 14 minutes and even hit the spin button. The fans went wild for that and everything else.

Nasty spin in the lane from Markelle Fultz to bury a hook over Winslow #TwitterNBAShow https://t.co/CFu1UNry3l pic.twitter.com/m42NSntWSy — Nate Duncan (@NateDuncanNBA) April 15, 2018

“Goose bumps,” Redick said afterward. “The crowd gave me goose bumps. Listen, it’s one game, and it’s 1-0 in the series. But as a basketball player, you dream about those moments where you’re in the second half of a playoff game and your team is making a run and your team is getting stops and you’re hitting 3s and the crowd is just energizing you and pushing you. It was awesome.”

It was a good night for the Sixers and the city, and the fact that it happened in the postseason—after all the moaning about losing and tanking—made it all the more special. The Sixers are an undeniable joy to watch, and they’ve become the darlings of everyone from, national pundits to anti-analytics truthers like Charles Barkley, but you have to remember that there remains a recalcitrant opposition force that hates everything the Process stands for. There are still straw-man arguments about how tanking affects psyches and hyperbolic columns about how the Sixers represent “a swift descent into nihilism” and those who stand against them, like the Heat, stand with “truth, justice and the American way.” If you ever wonder why Process fans are so insufferable and quick to say “we told you so,” that’s why.

Frankly, I don’t blame them. Admittedly, I might be a touch biased. But there were so many bad takes in Philly about the Sixers over the years that the people who endured them deserve to do a little chest-puffing and back-patting. (Though probably not this much.) Whether the Sixers make a deep playoff run or the Heat end up winning the series is immaterial to the greater argument. The debate is over. The Sixers are everything the loyalists always hoped they’d be, and it happened faster than anyone could have expected. They’re set up for right now and the future—despite the skeptics of the past insisting they were doomed to fail. When I worked in Philly, an old colleague—a really great guy otherwise—used to tell me that the Sixers sold their soul for a bag of magic beans. Something tells me he never actually read Jack and the Beanstalk.