The scrapbook isn’t empty, exactly. There are snapshots of prosperity sprinkled across the half-century and change in which the Nets have shared Greater New York with the Knicks. There have been stolen moments when the Nets have genuinely and honestly felt like the greatest basketball show in town.

There was May 10, 1974, a Friday night in Uniondale, when a raucous gathering of 15,934 people stuffed brand-new Nassau Coliseum to watch the Nets beat the Utah Stars 111-100 for their first ABA championship. On the court, rabid fans tore down the baskets as college football fans might ransack goal posts. In the locker room, Julius Erving — the single-biggest show in the sport — cooed as he chugged champagne:

“I’m not sure who’s bigger in New York right now, us or the Twin Towers!”

There was May 13, 1976, the last night a red, white and blue basketball would ever be used in competition, the Nets wiping out a 92-78 deficit after three quarters, riding Dr. J’s 31 points and 19 rebounds and thrashing the Denver Nuggets 112-106 to win the final ABA championship. Many of the 15,434 who were there (including 9-year-old me) swear that night was the loudest they’ve ever heard sports, anywhere.

“I think the Knicks heard us,” Erving’s brilliant sidekick, Super John Williamson, said after dropping 28 on the Nuggets. “At least I hope they did. We’re in the NBA now. We’re coming after them!”

There was May 2, 2002. The Nets had been playing in North Jersey for more than 20 years, but this was the first time old Brendan Byrne Arena truly sounded like it belonged in the big leagues, the 20,049 inside standing and rocking the gym from the opening tap right to the moment Indiana’s Reggie Miller drilled a 39-footer with 0.9 seconds in regulation to knot do-or-die Game 5 of the Eastern Conference opening round at 96-96.

So many times Miller had done exactly the same thing across the river, and Madison Square Garden (and the Knicks) could never quite gain their wind back. Not this time. The Nets ground through one overtime, and a second. Jason Kidd turned in perhaps his most brilliant game as a Net, scoring eight of his 31 in the overtimes. The Nets won, 120-109. They would play in their first NBA Finals a month later.

The next morning, early, over the phone, a bedraggled Nets executive, his voice barely a whisper, called a reporter, and said, “We beat ’em!”

“Who?” he was asked. “The Pacers?”

“No, man. Bigger than that.”

“The Knicks?” he was asked.

“Much bigger than that,” he said. “We had a bigger TV rating than ‘ER’ last night!”

Over the long term, of course, it has been a different story. Even in times of prosperity, the Nets have always been a stone in the Knicks’ shoe: an occasional annoyance, a periodic nuisance, but never a perennial threat. The Knicks had a 20-year head start on the Nets, for one thing. The Knicks were Manhattan. They were the Garden, first on 50th and Eighth, then at 33rd and Seventh.

The Nets were journeymen. They were the Teaneck Armory in Jersey for a time, and then they were the Island Garden in West Hempstead, and the Coliseum, and the Louis Brown Athletic Center in Piscataway, N.J., and then the Meadowlands. Even Brooklyn, their home since 2012, has been a fortress of Knicks’ loyalty since 1946.

“You narrow the gap with success,” Rod Thorn said in 2002, when the Nets were in the middle of a two-year run of back-to-back trips to the NBA Finals just as the Knicks were beginning what has become a two-decade plunge into purgatory.

Problem was, the Nets could never quite sustain that success. And even the move to Brooklyn, which could have been a flashpoint in the teams’ relationship, was decidedly muted; that 2012-13 season is the one outlier of the past 20 years, the Knicks winning 54 games and their only playoff series since 2000.

Even this season, when the Nets were ascendant — 42-40, a fun playoff appearance against the 76ers — and the Knicks were horrific — 17-65, fully engaged in tank mode even if nobody at Penn Plaza used those words — the difference was stark. The Knicks averaged 19,002 fans, good for ninth in the 30-team league.

The Nets averaged 14,941 in a building that seats 17,732. That’s 31st out of 31.

Last week, of course, came the seminal moment the Nets have long waited for. They agreed with Kevin Durant and Kyrie Irving on free-agent deals in excess of $300 million. It is a duo many had ticketed for the Knicks as recently as early June, and while Durant’s injury changed the dynamic a bit, the hard truth was still this:

The Nets got the stars; the Knicks got the scraps.

Brooklyn has become a destination; Manhattan a consolation prize.

Ergo: The Nets are primed to take over the town.

But are they?

On a certain level, this is always a silly debate even if it’s a fun one, perfect for saloons and water coolers and summertime tours through the talk-radio desert. Mostly, this has been a preoccupation among baseball fans because baseball is the one sport that, in this city of multiple franchises in every league, has actually seen the deed to its sporting soul passed around.

Hockey has always been the purview of the Rangers. The Islanders won four straight Stanley Cups from 1980-83 and the Devils won three in the nine seasons from 1995-2003, and while they ruled their respective fiefdoms … there was always a loud contingent of Rangers fans infiltrating the Coliseum in the ’80s and Continental Airlines Arena in the ’90s. There has never been much of a dispute here. New York is Rangers first and foremost.

Football? The Jets of Joe Willie Namath won a Super Bowl in 1969 and made impressive inroads in their first decade of existence thanks to his star power, but even as the Giants scuffled, they sold every available seat at Yankee Stadium. Bill Parcells and Rex Ryan have narrowed the gap through the years, but even Namath himself has conceded that trying to overtake the Giants is a futile task.

“We’re the underdogs in this town, always have been, always will be,” Namath said last year. “And I actually think most of us like it that way. It ought to give us an edge and make us a little salty.”

Baseball, though. For the first two decades of the 20th century, the Giants were an unassailable dynasty, often doubling and tripling the Dodgers and Yankees in terms of attendance, attention, newspaper space. The arrival of Babe Ruth in 1920 altered that paradigm forever, though, and while the Boys of Summer Dodgers occasionally poked their heads even with the Bronx Bombers, the Giants became an afterthought and by 1958 were beating a path to California alongside the Dodgers.

The Yankees-Mets dynamic, however, was from the start a unique one. The Yankees outdrew the Mets in 1962 and ’63 when the Mets were still quarantined at the dying Polo Grounds, but once Shea Stadium was built in 1964, they all but turned the Yankees invisible for the next 12 seasons, through 1975.

The Yankees retook the town with a vengeance in 1976, and three years later the Mets were drawing only 788,000 fans to Shea, but by 1984 another switch had taken place, and that would last until 1992. Since 1993, it has been a decidedly Yankees town and with each passing year it feels like that may be a permanent shift — even in the Mets’ World Series year of 2015 the Yankees drew 600,000 more fans and had consistently higher TV ratings — but history tells us not to be so quick to call it.

Now the Nets try to do what only the Mets have done in the last 60 years or so: Wrestle away from the dominant team the city’s soul and its primary rooting interest. Only twice in their shared history have the Nets outdrawn the Knicks — 1981 and 1982, when the Knicks’ fortunes had sunk so low they barely averaged 10,000 to the Garden. But that was more a backlash for New York than a boon for New Jersey.

Can it happen?

Perhaps the better question is: How has it not happened yet? Signing Durant and Irving ought to be the culmination of a perfect storm for the Nets. They reside in the trendier neighborhood. (It’s a fact that the bars and restaurants around Barclays Center are far more appealing, on the whole.) The Knicks have been a failing operation on the court and an embarrassing one off the court; neither Mikhail Prokhorov nor Joe Tsai has been spotted lately engaging forked-tongue fans.

The Nets are in capable, proven hands: Sean Marks and Kenny Atkinson; the Knicks are in still-unproven (at best) hands, Scott Perry and David Fizdale. And whatever disparity there is between them now, that is only certain to grow wider across the next few years, especially if Durant can approximate anywhere close to the player he used to be.

So are we looking at a Nets town?

Well, let’s go back to that Rod Thorn quote earlier. He said that to me one January night in 2002 as we watched the Nets trip the Spurs. The team he’d assembled on the fly — Kidd and Kenyon Martin and Richard Jefferson and Kerry Kittles — had already become (and remains) the most entertaining basketball show we’ve had in this area since the fabled Knicks of the ’70s.

There were 11,091 people there that night. Announced. In reality it was closer to 8,000. Thorn frowned as he saw all the empty seats. But understood.

“You narrow the gap with success,” he said. “But you close it over time. Look, people are serious with their sports teams. You aren’t just going to convince a guy to change his loyalties with one good year. You have to overwhelm them with success. And then you turn your eyes to the kids, the ones who don’t have years and decades invested in a team. And even then you don’t get there right away. You build. Over time, you try to build something.”

He laughed.

“It’s a cliché,” he said, “But Rome really wasn’t built in a day. But it was built eventually.”

And so, someday — and maybe sooner than we ever thought possible — might Brooklyn.