SEATTLE – The Sure Things are what they pay for. The Sure Thing is whatteams covet, so they don’t have to try and be smart. It’s tough being smart in the NFL. George Young was smart once; he decided to give an unknown football lifer named Bill Parcells a shot. He was the last one to have to be smart when interviewing Bill Parcells for a job. Soon enough, he became a Sure Thing, maybe the Surest Thing ever.

If you hire a Sure Thing, you don’t have to take a leap of faith, that’s the way the theory goes. As impressive as Eric Mangini may appear, as splendid the pedigree from which he emerged may be, he is the opposite of a Sure Thing. Legacies, reputations and jobs will ride on whether he is what the Jets want him to be, what they hope him to be.

But he is not Bill Parcells during the intervals in his career when he was Out but wanted back In. He is not Jimmy Johnson, the way he was after he left Dallas, or Bill Walsh when he left San Francisco, or Joe Gibbs during his long winter of exile from Washington. He is not what Bill Cowher will be if the Steelers are ever dumb enough to let him go, or what John Fox will be, or Mike Shanahan, or Bill Belichick.

He is not what Mike Holmgren was back in the winter of 1999.

Back then, Holmgren was the hottest coach on the planet, the man who’d gone to Green Bay and turned it back into Titletown, U.S.A., the man who’d channeled Curly Lambeau and Vince Lombardi and done what had seemed impossible, restoring glory to the smallest pro sports market in America. When it was clear he was suffering from wanderlust in Wisconsin, there was a parade of suitors eager to sign him up.

Not surprisingly, the winner was Paul Allen, the Seattle Seahawks owner, one of the richest men in the United States, a sports freak who wanted the very best for one of his prized toys. He gave Holmgren an eight-year contract. He guaranteed him $40 million. He gave him full control of the football operation. He gave him a fancy title, executive vice president.

He hired himself a Sure Thing.

And mostly, the Sure Thing came up wanting.

“It’s been an interesting few years,” Holmgren said earlier this week. “We had a plan and we wanted to execute that plan, but it took some patience.”

He’s won some games in Seattle. Until last week, none of them had come in the playoffs. Last year, the season ended in a brutal 27-20 postseason loss to a less-than-inspiring Rams team at home. Along the way came grumblings, and talk Holmgren would be fired, and the reality that he lost a significant amount of power and influence in an organizational shakeup a few years ago.

And then came this year, Year Seven of the original eight-year plan, and at last things happened exactly as Allen and Holmgren had hoped they would in January 1999. The Seahawks won 13 of 16 games, and their first playoff game since 1984. Shaun Alexander won the MVP. Matt Hasselbeck became established as an elite quarterback. The defense was ferocious. Their home field became a house of horrors.

“I think we’re a pretty entertaining team to watch,” Hasselbeck said.

For Holmgren, it is something else, a justification of all the faith and all the legal tender the Seahawks invested in him way back in the last millennium. He won’t say the words, because no coach would, especially a member of the Sure Thing alumni society. But listen long enough, and you can hear it. And understand.

“Did I feel we needed it this success? No more than normal, that part of it. Did I want it? Yes. All the things that were talked about . . . I joked about it but it was true. I’m human just like anyone else.”

Now, he is one step away from his third Super Bowl appearance in the past 10 years, and from the franchise’s first in its 30 years of existence. And the Sure Thing is on the verge of fulfilling an expensive destiny.

michael.vaccaro@nypost.com