Three years ago, the Brooklyn Nets were as dead as any NBA team has ever been. They had just wrapped a 21-win 2015-16 season. They had no young players of consequence. They had few draft assets; the Boston Celtics owned most of them through 2019 thanks to a trade that was and is considered one of the great heists in basketball history.

If Rondae Hollis-Jefferson signs with another team this summer, there will be zero players remaining from that 2015-16 outfit.

Just after the All-Star break that season, the Nets hired Sean Marks to be their new general manager. The team's Russian-based ownership group had been leaning until the very last minute to Bryan Colangelo. At All-Star Saturday night in Toronto, R.C. Buford, the San Antonio Spurs GM and then Marks' boss, approached Dmitry Razumov, then the Nets chairman, at a private event and told Razumov he might not even grant the Nets permission to interview Marks unless the Nets guaranteed Marks carte blanche to do the job the way he wanted, sources have told ESPN. Several other executives, including Bob Myers, the Golden State Warriors' president of basketball operations, chatted with Razumov that night about Marks' credentials. Brooklyn changed course.

The Nets had no first-round pick in the 2016 draft. Even so, Marks especially wanted to meet with one young player at the draft combine: Caris LeVert. Marks peppered LeVert with tough questions about his foot injury and how he might respond to Brooklyn's intensive sports science program. At the draft a few weeks later, Marks traded Thaddeus Young to the Indiana Pacers for the right to select Levert 20th overall.

It was the first move in the gradual reinvention of the Nets -- a remarkable story with very little precedent of a team that had nothing, worked every fringe avenue possible to find players and a measly three years later has somehow ended up with Kyrie Irving and Kevin Durant. (They also are signing DeAndre Jordan, i.e., the big man version of Jarrett Jack in that his primary value at this point appears to be that he is friends with better players.)

Unless free agency guts the Toronto Raptors, the Nets with Durant recovering from an Achilles tear will probably enter next season in the second tier of Eastern Conference playoff teams -- ironically, right next to the Celtics, who pillaged the Nets in that 2013 Paul Pierce/Kevin Garnett trade only to watch Brooklyn swipe a good chunk of their carefully planned rebuild today. Editor's Picks 2019 NBA free agency: Latest buzz, news and reports

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Irving is significantly better than D'Angelo Russell, but he does not by himself elevate a 42-win team into title contention. The hope is that the mega-leap comes with Durant's return in 2020-21.

And it is a hope, not a lock. Durant might never be the same player again. We all hope he is, because Durant before crumpling to the court in Game 5 of the NBA Finals was on pace to be (at worst) one of the 10 greatest players ever -- with an outside shot at breaking the all-time scoring record.

We just don't know. If Durant is 90 percent of his old self, a four-year max deal that might cap out the Nets going forward will be good value. If he's 70 or 75 percent or whatever figure you'd like to attach to "doesn't look the same," there is a downside to this contract that is unpleasant to think about. But even if he hits that 90 percent, it is hard to know what that missing 10 percent represents -- if it is the difference between an All-NBA player and a guy who can function as the best player on a championship team.

Being 7-feet tall with an untouchable feathery jump shot helps. That alone will make Durant a fun pick-and-roll partner for Irving, the way he was with Stephen Curry for three seasons -- only the Nets figure to lean on that action more than the Warriors did. Ever since the rumblings about Durant and Irving joining forces burbled up, there has been noise within league circles that perhaps they will not fit all that well together -- that they will suffer from the "only one ball" problem.

Nah. They are both elite shooters who carry immense value away from the ball. The defining quality of Durant's on-court career is his ability to play alongside superstar teammates without sacrificing any of what makes him great or taking away anything that makes those teammates great. He is in some stylistic ways -- namely, time spent controlling the ball and the offense -- the greatest second option of all time.

Joining with a ball-dominant point guard dashes any dreams of seeing Durant fully unleashed as the undisputed No. 1 option. There will be no permanent Slim Reaper posting 33-9-9 lines over full seasons. Working with Irving might resemble his partnership with Russell Westbrook on the Oklahoma City Thunder.

And that's fine. Durant as he recovers from traumatic injury and ages into his 30s will need a younger All-Star to carry chunks of the offense the way LeBron James needed Irving to win a title with the Cleveland Cavaliers. They will form a lethal, switch-proof, pick-and-roll combination that works both ways: Durant screening for Irving, and vice versa. Remember: Irving has a long history working that action with James.

But that is a year away. How Brooklyn builds out its team around its new stars will be intriguing. The Nets can retain all of LeVert, Spencer Dinwiddie, Joe Harris, Jarrett Allen, Rodions Kurucs and whoever else is leftover once they make room for Durant and Irving. They have agreed to sign Garrett Temple, per reporting from Marc J. Spears of The Undefeated. They still need frontcourt depth; they might bring back Jared Dudley, sources say.

Look at those names. The Nets got Dinwiddie and Harris for nothing. Any contender would welcome them now. They selected Allen with the pick -- No. 22 -- they received from the Washington Wizards in exchange for a half-season of Bojan Bogdanovic. At 27, Harris is the oldest among the younger foundation. Together with Russell, they comprised the core of a feisty postseason team.

Reaching that status in the East is not some crowning achievement. But the Nets did it with young players they could sell as long-term pieces of a good team. They could credibly look Irving and Durant in the eyes and say: See what Russell and these guys did together? Imagine what you might do.

Brooklyn selected good character players and built a culture of work, selflessness and fun around them. The Nets could feel it coming together in 2016-17 -- the first season for both LeVert and Kenny Atkinson, the head coach charged with the league's toughest rebuilding challenge. At a team dinner before their last game that season, Irina Pavlova, then president of Onexim Sports and Entertainment Holding and liaison between the team and its Russian owners, fought back tears as she stood to give a toast, players and coaches recall. "In my seven years here, this is the first time it feels like a team," she said, "and not just 15 players on a roster."

The Nets weren't perfect. No team is. They got lucky when other teams matched their grandiose offer sheets, then inexplicably spat in the face of that luck by trading for Allen Crabbe on the same toxic deal Brooklyn had foisted upon the Portland Trail Blazers.

But the Nets hit way more than they missed. They built a cutting-edge practice facility in Brooklyn and housed it with one of the best sports science staffs in the league. They encouraged players and coaches to bring their families along. They resisted the temptation to microwave a 45-win team by splurging on veterans. They refused to tank, even this season, when they finally had their pick back. They would play hard and try to win.

"Once they win, they will get everyone they want," Luis Scola told me in the summer of 2017, after playing part of just one season in Brooklyn. "But all those other things don't matter until you have a good team."

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LeVert has a chance to grow into a championship third option, which is probably his appropriate NBA ceiling. He is still just 24, with potential to become an All-Star, two-way wing. His jump shot -- he is a career 32.9% shooter from deep -- might be the swing factor. The presence of Irving and Durant ensures Levert will not be overburdened as a primary on-ball creator.

LeVert is eligible for an extension now, and the salary attached to it will be big. But if he improves, it will be at worst a movable contract. Dinwiddie is on a bargain deal. Allen has two years left on his rookie contract. Harris is a free agent after next season, but his market will go only so high. Even if the Nets don't have much (or any) cap room in the Durant-Irving era, they will have the flexibility to pivot in other directions -- including chasing a third star.

Irving will have to prove he is not toxic to team chemistry. It helps that even while injured, Durant will hover over him, the true franchise alpha. The Nets are betting Atkinson's fearless, sometimes loud style will work better with Irving. Atkinson will not back down.

Regardless of what comes next, this is a historic day for the Nets. It is the transformational point of one of the most stunning reconstruction projects in recent sports history.

It is obviously a gut punch for the New York Knicks, who traded their own franchise player to unlock cap space -- and, sure, for lots of other reasons -- and have no major player to spend it on. Their buffoonish owner, James Dolan, took the unusual and bombastic step of boasting during a radio interview in the middle of the season about how the Knicks would "have a very successful offseason when it comes to free agents" -- how players and their representatives had told them so.

Perhaps when you have almost zero record of competent team-building over two decades, you should hold off on the premature braggadocio. Just a thought. Our Adrian Wojnarowksi and Ramona Shelburne reported late Sunday that New York was not prepared to offer Durant a max contract due to concerns about how he might recover. Fair. Where was this caution in 2010 when the Knicks signed Amar'e Stoudemire?

The Knicks will spin about how they are well-prepared for the future with RJ Barrett, some other young players who might or might not amount to much, extra picks from the Dallas Mavericks via that Kristaps Porzingis deal and cap space they might theoretically use at some point on someone better than Stoudemire (or, you know, Porzingis). (Julius Randle, New York's big Day 1 signing on a three-year, $63 million deal, would have made for a nice fit next to Porzingis.)

They're not entirely wrong. But they are stung at Madison Square Garden -- and embarrassed. They were not able to show Durant or Irving proof of concept the way the Nets did with Russell and Brooklyn's young team. So on we go, to do this again next summer and the summer after that.

The Warriors hurt too, and they will forever have to contemplate how they handled Durant's final chapter with the team -- from Draymond Green deriding him in that infamous November game against the LA Clippers to the fateful decision (made in conjunction with Durant's doctors) to clear him for Game 5 of the Finals.

But they knew this was in play when they signed Durant three summers ago -- that he might win with them, then seek his own path. The Warriors were never going to be his team. He knew that. They felt it. Durant went through periods when he was distant and quiet. A lot of people within the organization were convinced in the middle of the 2017-18 season that he would leave that summer, sources have said.

Golden State can never come close to replacing his talent. The Warriors did get more wiggle room filling a roster that looked perilously thin in the Finals without Durant (and then Klay Thompson). (Again, there is downside to Durant's new contract.) Using it to turn Durant's departure into a sign-and-trade for D'Angelo Russell -- on a max contract -- is a bold and risky asset play.

It will cost them Andre Iguodala, a cultural touchstone. His departure, almost more than Durant's, marks an end to an era. The Warriors will never look the same without him. More importantly: Golden State will have to attach a lightly-protected 2024 first-rounder to dump Iguodala's contract onto Memphis, as reported by Wojnarowski. That pick has some upside for Memphis. Golden State has time to acquire a replacement, and they will need picks to transition into the post-Splash Brothers era.

Russell will have to prove he is worth this, and the proof may be in whether the Warriors can flip him for value once Thompson returns. In the meantime, he fills a hole and allows for Steve Kerr to scale back Stephen Curry's minutes. But Russell's fit with Curry and Thompson is not clear. He is making too much to come off the bench.

Yeah, the Warriors are getting both weirder and older. They haven't exactly killed it in the draft since 2012, which is really not a fair criticism considering where great teams draft. Green is up for a massive extension that would vaporize a lot of that cap-and-tax flexibility. Thompson might not be the same until the 2020-21 season after tearing his ACL in Game 6 of the Finals.

But count the Curry/Thompson/Green trio out at your own peril. Their record when Curry played and Durant did not was a sterling 34-4 over three seasons, before the Finals against Toronto. And even against a great Raptors team, the Warriors went 2-3 in games Thompson played -- including Game 6, when he left late in the third quarter with that knee injury. Who knows: Had Thompson stayed healthy for the duration, the Warriors might have won the whole damned thing in Game 7 in Toronto.

The Warriors will be good, even amid a Western Conference in which the Utah Jazz, the Los Angeles Lakers and a few other teams are loading up to take a run at their throne. They might even contend again once Thompson recovers.

But the Warriors' ceiling will never be the same without Durant. They have to restock the depth they jettisoned to get him.

It was worth it, though: two titles and heavy favorite status for a three-peat until Durant's calf betrayed him. Now Brooklyn gets its chance -- sooner than anyone could have reasonably expected three years ago, when Durant signed with Golden State. What a turnaround.