A Tuesday night in Oakland, and a baseball game inches toward first pitch before a minuscule quorum of witnesses. It’s mid-May, and already this feels like a schedule-filler, a contest between a pair of bottom-dwelling franchises with almost nothing in common except an underlying sense of angst about their futures.

Things are so deathly quiet within the stained concrete bowl of the Coliseum, the plumbing-impaired home of the Athletics, that there’s room for individual expressions of emotion to go viral: a lone clap along the third-base line for each member of the visiting Miami Marlins’ starting lineup; a peanut vendor belting out a sales pitch from behind home plate; and a stray voice from somewhere in the upper deck shouting a denigrating slur at lame-duck Marlins owner Jeffrey Loria, who is likely lounging in a sprawling manse on the other side of the country, paying no mind to any of this.

Down the first-base line, a man leans atop the visitor’s dugout during the tail end of batting practice, clutching a souvenir magazine and wearing the jersey of a promising 25-year-old Marlins outfielder named Christian Yelich. The man in the Yelich jersey is speaking to a guy in an A’s T-shirt bearing the name and jersey number of long-departed slugger Josh Donaldson, and they are discussing the vagaries of autograph-seeking with all the urgency of a pair of fishermen on a bridge. Some of this involves identifying the largely anonymous major leaguers on both teams’ rosters; much of it involves wondering if it’s even worth the effort to stand here.

"Worst-case scenario," the Yelich guy says of his Marlins, "they’ll be back in San Francisco in July."

The good news is that there are no beer lines. In fact, there are no lines for anything at all. It is a stubbornly pleasant Northern California evening, and there is nothing at stake, and there’s only one thing novel about what’s about to occur: This is the first interleague game of the A’s season, in the midst of the 20th anniversary of interleague play in Major League Baseball. And the milestone has landed in Oakland in near-complete silence.

How is this night different from all other nights in baseball history? Maybe it’s not. But it’s enough to make you wonder what it means for baseball’s future when one of the most contentious ideas the sport has ever known becomes so utterly normalized that no one much bothers to argue about it anymore.

"Look," Bud Selig says. "I didn’t say every one of them was good."

Selig has been patched through to my cellphone from his office in Milwaukee, and he’s just told me about how fascinating certain interleague matchups can be, and I’ve countered by telling him I attended A’s-Marlins the night before as part of an attempt to capture the full scope of interleague play as it approaches it 20th anniversary. It is one of those milestones that’s gone almost entirely unnoticed, but here we are: On June 12, 1997, the San Francisco Giants traveled to The Ballpark in Arlington to face the Texas Rangers — because who was not clamoring for that rivalry-in-waiting to be consummated — thereby shattering the roughly century-long taboo that the American League and National League remain sequestered from each other in games that count in the standings, until the World Series.

It either marked the death of one of baseball’s most enduringly unique notions, or it was the end of a silly and pointless division that benefited no one and left millions of dollars on the table. By the time it came about, most everyone in power — including Selig, the former commissioner who advocated for interleague play for decades and succeeded in getting it approved unanimously by the owners — was in the latter camp. Over the course of the ensuing decades, interleague has evolved from a novelty into an everyday occurrence, with a rotating series of matchups that afford us, as fans, the curiosity of Mets-Yankees or Cubs–White Sox or Red Sox–Cardinals, but just as often leads us down abandoned alleys like the one in Oakland.

And I realize that I’m trolling Selig by bringing up that A’s-Marlins game. I realize that, by virtue of my own geographic placement and my impending deadline, I have chosen to attend perhaps the worst imaginable interleague matchup. Even Selig acknowledges the criticism that certain interleague matchups are inherently boring. But I also accept Selig’s counterpoint, which is that a lot of intraleague matchups are just as dull; the announced attendance of 12,835 for that Marlins game was nowhere near Oakland’s worst crowd of the season (10,292 for a May date with the Angels) up to that point, with several divisional matchups faring even worse. (The next day, the A’s drew nearly 20,000 in the afternoon for the second and final game of the series.)

"I think it benefits not only the fans, but the game as a whole," A’s assistant general manager Dan Feinstein tells me. "It breaks up the monotony of seeing the same teams all the time."

So there were larger market forces at work in the spiritual emptiness of A’s-Marlins than just interleague play, but this was also what was so remarkable to me when I started asking questions about it: that no one even seemed to think much about it at this point. That a compelling or terrible baseball game between a National League team and an American League team is now viewed through the same lens as a compelling or terrible baseball game between division rivals. That interleague play has become so routine that even traditionalists — "I consider myself a traditionalist," Selig says — have largely stopped thinking about it as anything nontraditional at all. That, at times, those 20 interleague dates per team each season will draw a few more people, but that, at other times, it won’t make much of a difference. That it is just there.

"I don’t think people resist the concept of it anymore," says Chris Marinak, MLB’s executive vice president of league economics and strategy. "I think every sport has some element of universal play across the entire league."

"It’s part of life now, no question," Selig says. "I haven’t read a negative column on interleague play in many, many years now."

This will not be that column, either. Yet the fact that it’s part of life also means that interleague play can’t really be trumpeted as "special" anymore. Back in 2013, when Major League Baseball balanced out each of its leagues to include 15 teams, it was faced with little choice: It would have to play interleague games every day to make the schedule work. Nobody particularly liked this idea, Selig included, but what’s happened since then has been kind of remarkable in terms of structure. According to research by The Ringer’s Zach Kram, 66.6 percent of interleague games from 1999 to 2012, when the interleague calendar solidified without any year-to-year changes in scheduling format, were played on weekends; since then, 34.8 percent, or roughly half that number, have been played on weekends. And among the "rivalry" games that sold baseball on adopting interleague play in the first place — Yankees-Mets, Cubs–White Sox, Royals-Cardinals, etc. — 87 percent were played on the weekend from 1999 to 2012, and only 22.1 percent have been contested on the weekend since.

It is perhaps the starkest indication that interleague play has been so fully integrated into the schedule that it doesn’t carry as much weight as it once did. Not surprisingly, attendance at interleague games — which was 7 to 20 percent higher than overall attendance every year between 1997 and 2012 — has dropped considerably since 2013, to the point where it isn’t much different than the average attendance for a typical major league game.

None of this is meant to suggest that interleague play has been an utter failure. Selig is right when he tells me that it has boosted attendance in certain cities; he’s right when he tells me that it has created additional television interest in the game. He’s also right when he tells me that baseball had long been "very resistant to change" when he began questioning the wisdom of some of its intransigence decades ago.

"I just knew this was the kind of thing baseball should be doing," Selig says. "We did a lot of things traditionalists didn’t like [during my tenure as commissioner]. At some point, you’ve got to what you’ve got to do."

But it’s worth recalling why interleague play was once a controversial idea, and what it might mean now that it isn’t. As Selig’s successor, Rob Manfred, continues to tinker with rules changes that tweak the game’s basic structure — a pitch clock, an intentional walk entirely devoid of action, a prohibition on ceaseless mound visits — he is constantly wrestling with an unspoken subtext: Baseball’s inherent conservatism — its "reasonable reluctance to tamper," as columnist and author George Will puts it to me — is part of what made it so popular in the first place.

This needs to be balanced out with the realities of a changing marketplace, and with the evolving attitudes of baseball’s fan base. But even Will, the most well-known conservative baseball fan in America, says that he’s "building his summer around Mike Trout’s visit to Washington" for an interleague game between the Nationals and Angels. "The game’s changing all the time," says Will, who worked on Selig’s Blue Ribbon Panel on Baseball Economics in the 1990s (and considers Selig the greatest commissioner in baseball history). "Whether we want it to or not."

"The one constant among the generations," baseball’s official historian, John Thorn, tells me, "is that the golden age of baseball coincided perfectly with when you happened to be 12 years old."

But this is precisely why the interleague debate was important: because it got at baseball’s fundamental argument about balancing tradition with modernity. And with every change that’s made, the game has to weigh what it’s sacrificing — and what those sacrifices might mean for its future.

In 1970, a young accounting professor at Boston College took a job working as the controller at the American League office. That professor, John Harrington, was naïve and new to baseball; his boss was the "ultraconservative" Joe Cronin, a Hall of Fame shortstop who’d spent most of his career playing for the Red Sox. And every year when the World Series and the All-Star Game came around, something odd happened: Cronin would become furiously competitive. He hated losing to the National League, resented its perceived arrogance as the "senior circuit," would get so heated at longtime NL president Chub Feeney that he often couldn’t even bring himself to speak to him.

"I loved it," Harrington — who became co-architect of baseball’s interleague proposal as CEO of the Red Sox in 1996 — tells me from his home on Cape Cod. "I couldn’t believe the intensity. Cronin and Feeney were worlds apart in their approach to the game."

Where did this animosity come from? In a way, it stemmed from a dispute that began in the late 19th century, long before either Cronin and Feeney were born. It harkened to a time when interleague games were actually commonplace, even if they didn’t count in the standings: As far back as 1877, National League clubs would compete in games against teams from its predecessor, the National Association, while traveling by train from one city to the next for their regular-season contests.

"They were exhibition games," Thorn says, "but they occurred during the regular season."

It took several decades and multiple missteps by the National League, but by 1901, the American League had formed as its chief rival. And by the time the leagues made tenuous peace in 1903, and set up the first World Series that same year, they had separate offseason meetings, and separate rules (the foul strike, Thorn notes as an example, was adopted by the NL in 1901 and by the AL in 1903). There were still exhibition games between the leagues, but the notion of regular-season interleague play became anathema as the leagues began to cling to their own identities. And through sheer momentum, that idea carried on for nearly a century.

No other professional sport had anything remotely like this. There was contentiousness between the AFL and the NFL, but then they merged, and now there is no fundamental difference between the AFC and NFC except the television network that airs their games on Sunday afternoons. (This is also why the Pro Bowl is the dumbest event on the NFL calendar.) The NBA and the NHL essentially have conferences for the express purpose of minimizing travel and determining playoff seeding (and their All-Star games are equally frivolous).

Yet baseball had two leagues that carried a fundamental animosity for each other, even when no one was old enough to remember exactly how in the hell it started. They existed on separate tracks for the entire summer. And why was it that way? Because it had always been that way. In the 1940s, Bill Veeck, the bohemian owner of the Cleveland Indians, brought up the notion of interleague play (his father, Bill Veeck Sr., had first raised the notion in the 1930s), and it got nowhere; in 1973, Selig, as a young owner in Milwaukee inspired by Veeck’s unconventional thinking, raised it once more — he even called it the "Feeney Plan" to pacify the ego of the National League president.

"We were going to have six games right before or after the All-Star Game," Selig says. "And by God, we got to the summer meetings here in Milwaukee, and the American League voted unanimously for it, and the National League voted it down."

This is one reason why the baseball All-Star Game felt like it held some actual weight (and why Selig’s attempts, post-interleague play, to prop the game up by imposing meaning upon it by awarding home-field advantage in the World Series to the winner, rang so hollow): Because it was both a manifestation of that rivalry and a unique occurrence, an opportunity for fans to see the matchups between pitchers and hitters who may not have otherwise crossed paths. It was, in the age of limited television exposure, a momentary violation of taboos.

"It’s like saying if you compare a virginal Victorian dame to a stripper — the more clothing, the more mystery," says Thorn, who, unlike Selig, feels that interleague play’s primary negative impact has been to dilute the purpose of the All-Star Game. "I’m in the odd position of being an advocate for the mystery. It’s as though I showed up to a strip joint and was the only one yelling, ‘Put it on, put it on, put it on!’"

But over time, as television’s reach grew, as information became more readily available, the idea of that virginal separation between the leagues began to feel more and more quaint. And then came the 1994 work stoppage that canceled the World Series, and baseball’s internecine fights began to seem like more of a liability than a strength. In the aftermath, all that tradition for tradition’s sake began to seem foolish, particularly when it didn’t benefit the sport’s paying customers. This helped allow Selig to expand the playoffs and to impose revenue-sharing measures and smooth over labor disputes and preside over the construction of an entire generation of retro-chic ballparks. And it allowed the owners to finally acknowledge that there was no good reason not to have interleague play.

"The change in society and the presentation of the game is so vast that to maintain the separation between the leagues seems perhaps pointlessly quaint," Thorn says. "Just like if you go to an Orthodox synagogue, the women and the men have to go to separate sections. But they’re together beforehand, they’re together afterwards. Why do they do it? Tradition."

Amid all these advances, baseball finally consolidated in 1999, shuttering its American League and National League offices and confining the operation to one New York skyscraper. The title of "league president" is now largely honorary. The Brewers jumped from the AL to the NL in 1998; the Astros jumped from the NL to the AL in 2013. What it all means, Thorn tells me, is that there is no rivalry between the leagues anymore — there isn’t any fundamental difference in the way they operate or the way they view each other, particularly now that they compete against each other every day of the season.

All that’s left is the firewall between them, the one thing that interleague play was potentially set to resolve, once and for all.

And it turns out it hasn’t resolved anything. It turns out that this may be the most compelling fight baseball has left.

I am speaking, of course, of the designated hitter, which began as an experimental three-year pilot program in 1973 (despite, Harrington tells me, the reluctance of Cronin, the American League president), and which has carried on for nearly 50 years in the American League — and been beaten back repeatedly over that same period by the National League. It makes no logical sense that the leagues have consolidated in every other way but still have this strategic chasm between them; back in 1996, when interleague play was on the verge of being approved, both leagues appeared ready to eliminate the DH altogether to make things uniform. But, with good reason, the players’ association objected to the idea.

"If you started all over without having the DH as it is now in the American League, you probably would never have the DH," former Phillies owner and current honorary National League president Bill Giles, a longtime advocate for interleague play and the son of longtime National League president Warren Giles, tells me. (Giles also told me the Phillies nearly cast the deciding vote for a DH in the NL in the late 1970s, but Giles couldn’t reach the team’s owner, Ruly Carpenter, who was fishing in the Atlantic Ocean.) "And the reason I say that is a DH gets $15 million a year, and your extra pitcher the National League teams have makes the minimum."

This disparity means that interleague games will remain (at least on one level) an inherently odd crossing of the streams, particularly in National League ballparks, where certain at-bats by certain pitchers often devolve into bizarre performance art. "The pitchers — it’s funny," says the A’s Feinstein. "Some of them get really fired up to go and hit. Some of them haven’t done it since high school and they take their batting practice seriously and they take their at-bats seriously. Other pitchers [maybe] out of fear of embarrassment don’t even like taking the bat off their shoulders."

There have been intimations since then that maybe baseball will eventually evolve toward a universal designated hitter; players union head Tony Clark was asked about the idea in the run-up to the most recent collective bargaining negotiations in 2015 (though a union spokesman told me that quote was largely taken out of context). The fact that the AL has won more games in interleague play every year since 2004 has also fueled that conversation (even though it appears the AL’s dominance may be due to factors that go far beyond the DH).

But perhaps the most remarkable thing about interleague play is that, even after two decades, it hasn’t even begun to resolve the DH question. If anything, it’s reinforced the fundamental differences between baseball’s hyperintelligent partisans: While George Will tells me he prefers the National League game because of the more intricate strategy involved, John Thorn tells me he used to hate the DH, and now he loves it, because there is nothing more infuriating than watching an American League pitcher mime his way through an at-bat.

"I’m a bit surprised that interleague has not altered [the DH discussion] at all, as far as I can tell," Will says. "Major League Baseball still thinks it benefits from the argument. The real traditionalists now like the leagues having a somewhat different pace and tempo and strategy."

"I think the status quo is the place we want to be," says Marinak, the MLB executive vice president. "I think you have heated debates on both sides of the aisle, and you’re never going to get a consensus as to going one way or the other."

This makes no logical sense, which is why the inconsistency drives certain people insane. But it makes emotional sense. Because now that interleague play has smoothed out every other difference between the American League and the National League, this is the one thing standing between baseball and the utter homogeneity of the other professional sports. There is something to be said for baseball bucking tradition and embracing modernity, as it did with interleague play, and there is something to be said for baseball refusing to fully cave in to short-attention-span theater, as it has done by continuing to advocate for the excruciating sideshow of watching pitchers hit in National League ballparks. It is a delicate balance, and the dichotomy of the DH manages to preserve baseball’s contentious dual-track NL-AL history while also offering fans a choice. It’s become its own tradition, and even interleague play hasn’t been able to break it.

And maybe I’m only saying this because that’s the way baseball was when I happened to be 12 years old. But sometimes, tradition for tradition’s sake isn’t such a bad thing.