The 2017 NBA offseason was perhaps the most intense and relentless summer in the league's history. Already in the midst of an era of star movement, a handful of big-name players switched teams again, and much of it happened with surrounding drama. But there was a method to the madness. Here's a look at everything you may have missed (or forgotten) in the offseason and what it may mean.

2017 was really about 2018

Transaction season truly started in February, when DeMarcus Cousins was traded to the New Orleans Pelicans. Many of the star players who were moved in the following months had the same thing in common: They will or can be free agents in 2018. Other moves were about setting up cap space for 2018.

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Cousins was in position to be traded as the Sacramento Kings tried to get out ahead of a possible contract impasse in 2018. The same situation played out with Paul George, who was traded by the Indiana Pacers to the Oklahoma City Thunder. Isaiah Thomas, who is headed for a potentially complex 2018 free agency because of a hip injury, was moved by the Boston Celtics to the Cleveland Cavaliers.

It's even relevant for Chris Paul. He was involved in a blockbuster trade before he became a free agent and picked up a one-year option as part of his move to Houston. He will be a free agent next summer, too. Of course, LeBron James can be a free agent in 2018, as can Carmelo Anthony and Russell Westbrook, if they choose.

The Lakers have been most aggressive in clearing and protecting cap space for next summer. Before drafting Lonzo Ball, they sent D'Angelo Russell and Timofey Mozgov to Brooklyn for Brook Lopez, who comes off the books next summer. It's a safe bet they will be looking for ways to offload Luol Deng's contract as this season unfolds.

Although there was more huge spending throughout the summer, the money dried up for some free agents. Lower cap projections for the future and concerns about luxury tax spending chilled the market a bit by mid-July as teams started thinking more about their 2018 books.

Warriors win again

One of the major reasons a handful of teams chose to focus more on 2018 is because the Warriors show no signs of slowing. They successfully navigated a bit of a challenging summer but ended up in a clean sweep as they re-signed Kevin Durant, Steph Curry, Andre Iguodala, Shaun Livingston, David West, JaVale McGee and Zaza Pachulia. They also added more shooting in Omri Casspi and Nick Young. Marcio Jose Sanchez/AP Photo

This was expensive. Curry landed a $200 million deal, and Iguodala used some leverage to squeeze the Warriors into a three-year, $48 million deal. The Warriors, amazingly, have never paid the luxury tax in team history. Those days are about to end in a big way. But the Warriors saw more than $90 million in profit last season and have a new arena on the way that promises to unlock a treasure chest of revenue, so don't worry about them.

Boston takes some risks

The Celtics had a wonderful 2016-17, enjoying a rebirth as a championship contender and an attractive playing style where the collective was often able to triumph. But the front office saw an overachiever, which is probably accurate, and so they went on a mission to essentially blow it up. They will have four new starters this season. They sacrificed several role players to open cap space to sign Gordon Hayward. They traded their most popular player, Thomas, for Kyrie Irving in a deal that could alter the course of two franchises.

Rebuilding a contender on the fly takes guts and power, which Danny Ainge has. But he stuck his neck out by trading down from the No. 1 overall pick and proudly stating that he'd have taken Jayson Tatum, whom he drafted at No. 3, ahead of No. 1 overall pick Markelle Fultz anyway. That's a choice that could shape Ainge's reputation, either way, in the future.

He also elected to stay on the sidelines for Jimmy Butler and George when they were dealt, although he clearly had the assets to beat the offers the Minnesota Timberwolves put forth to land Butler and the Thunder made to get George. Instead he cashed in some big chips for Irving, who has a ring but doesn't have the same two-way résumé as George or Butler. We'll see how it works out.

Unprecedented coaching stability

Over the past year, the Lakers, New York Knicks, Indiana Pacers, Cavs, Atlanta Hawks, Orlando Magic and Los Angeles Clippers have changed leadership in their front offices. Phil Jackson got fired by the Knicks a few days after making a vital draft pick (Frank Ntilikina), and with $24 million left on his contract.

David Griffin couldn't come to terms with the Cavs despite three historic years as GM, kicking off a wild few weeks in Cleveland. Mike Budenholzer and Doc Rivers were both essentially demoted, losing their personnel control. But the 2017-18 season will open with the same 30 coaches as a year ago. This is unprecedented in league history.

The last coach to be fired was Dave Joerger by the Memphis Grizzlies back in May 2016, and even he immediately got another job in Sacramento. Does this mean the NBA is in a golden era of great coaching? Don't count on it. Yes, many teams are happy with their coaches, but insiders are already sensing a bubble. There could be a rash of warming seats and then changes as the season unfolds.