Bill Belichick was once Bill Parcells' chosen successor. They went six years without speaking.

So what happened? Bill Parcells is ready to tell all.

In a new autobiography titled Parcells, the Hall of Fame coach reveals that Belichick betrayed him in the late 1990s. According to Parcells, the pair had an agreement in place in which Belichick would take over as coach of the New York Jets once then-head coach Parcells retired.

Only two days later, Parcells received a resignation letter from Belichick, who had just accepted the head coaching job in New England.

At the same press conference where he was intended to announce his new future with the Jets, Belichick instead announced he was leaving. Parcells took it badly, and the two avoided each other until resolving their differences in 2006.

"He made a deal and then tried to get out of it," Parcells writes. "A deal's a deal. You want out? You're going to pay. Simple."

Allegedly, Belichick turned down the Jets job because the team's ownership situation was unclear at the time, and that created insecurity about his future with the team. That decision has fueled an intense rivalry between the Jets and Patriots over the years, with Belichick getting most of the laughs.

In his book, Parcells says the two have since moved past their differences and are back on speaking terms. The coach even says he doesn't "begrudge" Belichick for going to New England.

But Parcells, who led the Patriots to the Super Bowl after the 1995 season, does credit himself as the likely reason the Patriots hired him in the first place.

In other words, Belichick would be nothing without Parcells. Yep, sounds like everything's hunky-dory now.

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