Erik Spoelstra signed a four-year contract with the Miami Heat on the eve of training camp and may be one of the biggest reasons why LeBron James also re-commits to the franchise this July.

"They're more intertwined than they've ever been," says a league source closely connected to James and Spoelstra. "LeBron knows he plays for one of the elite coaches in the game, and that maybe wasn't the case when he got there."

Spoelstra has never let the story become about him and has been relentless in remaining innovative. Spoelstra has studied football teams that use the spread option, which helped him develop position-less basketball.

Spoelstra and James were strangers when their partnership began in 2010 and he survived calls for his firing when the Heat struggled initially in 10-11.