Report: Durant got 'frustrated' with Westbrook, thought Thunder peaked

Many fans across the league were perplexed by Kevin Durant's decision to leave a championship-ready organization like the Oklahoma City Thunder.

In addition to the fact that Durant could've earned far more money had he stayed put, his pairing with a fellow top-five player in Russell Westbrook and a host of useful role players propelled the Thunder to the Western Conference Finals in four of the last six seasons.

So why did Durant leave?

Apparently he got "frustrated" with Westbrook, and felt like the team had "plateaued," a source told Howard Beck of Bleacher Report.

"Ultimately he got frustrated and felt that they had plateaued," said a person with insight into Durant's thought process. "(Billy Donovan) came in, and he still had the same issues that he had with Russ under (Scott Brooks). The offense didn't change much. He still had to take a ton of contested shots every game; and that's when he had the ball at all."

For almost the entirety of their eight seasons together, there was an ongoing debate about who should be the lead dog in OKC. Both Durant and Westbrook were worthy of taking over - but there's only one ball.

Last season, it was Westbrook who led the Thunder in usage despite Durant being the far more efficient scorer.

The Thunder also favored running isolation-reliant offenses, and that might be what prompted them to change coaches, but those same problems persisted when Donovan took over for Brooks.

Durant wanted to keep the ball moving, but the Thunder ranked dead last in passes per game.

The Warriors, perhaps cognizant of KD's frustration, pitched him on how much easier he'd have it in Golden State. Head coach Steve Kerr runs the league's deadliest offense, which is predicated on passing, cutting, and shooting.

Related - Jerry West told Durant he would have it easier in Golden State

Introducing Durant will still be a challenge, though. If the Thunder had trouble getting two stars to co-exist, how will the Warriors manage four?