PHOENIX - Why should one team be so rich at safety when so many are poor?

The question isn't one that could be compared to, say, economic distribution because the Seahawks acquired Earl Thomas and Kam Chancellor through a system that was designed to create equality - the draft.

But it's one that has been asked by many teams across the NFL - the Eagles included - that have failed to find talent at a position that has increasingly become difficult to adequately fill.

The simple answer, although only in theory, not practice, would be to draft players like Thomas and Chancellor. Seattle coach Pete Carroll would be the first to say that his fifth-year safeties make his job and that of defensive coordinator Dan Quinn that much easier. Thomas and Chancellor would likely thrive in any scheme.

But Carroll's core base defense, one that he established many years ago and has stuck to since, also allows for his safeties to max out their abilities. It's a scheme that is uncomplicated, adaptable and relates to the functionality of Carroll's entire philosophy.

Almost all coaches say they cater their schemes to the skill sets of their players, but few have a system that is as practical or are as willing to change. There have been times over the last two seasons when the Eagles defense has seemed incapable of adjusting.

Single safety man-to-man defense, anyone?

Now that may be partly because the safeties, for instance, were Nate Allen or Patrick Chung, but the Patriots found a way to make Chung work this season and he'll be playing in the Super Bowl against the Seahawks on Sunday.

Good coaches find ways to make not-good players work within their schemes. Great coaches like Carroll take great players and create great - like all-time great - defenses.

"We try to find unique qualities that our guys have - and it's not just because we are here in Seattle and we have those safeties, it's always what we've done across the board - and put them in the position to do things that they're really good at and really accomplished at," Carroll said on Monday. "And then we try to grow their roles from that.

"We found that when you do that, the players can have success early in their career and they can start to develop confidence and some success that they can build on. And it's always worked out really well. It's on coaches to have the flexibility to adapt your scheme to match your players' unique qualities."

Carroll admitted that there isn't anything overly complex about his scheme. There are subtle nuances, and he doesn't have to trick anything up because the "Legion of Boom" secondary can play most offenses straight up.

Thomas mostly plays free safety and is clearly the best centerfielder in the league because of his speed and ball skills. But Carroll doesn't ask him to play out of his comfort zone. Thomas is responsible for post and seam routes over the middle against the pass.

Chancellor is the strong safety. He'll play back and Thomas will play up near the box at times, but they aren't as interchangeable as the Eagles' safeties, for instance. Chancellor's strength is playing against the run and being a physical presence over the short middle.

Carroll has clear-cut responsibilities for his safeties in whatever role and it's their job to execute.

"It's clear and cut. It's basic. It's simple," Chancellor said of the Seahawks' scheme. "Whether it's me in the box, whether it's me playing man coverage, whether it's me being a 'Robber,' whether it's Cover 2, it's just plain simple rules. And after that it's just being a football player."

The Eagles signed Malcolm Jenkins to a free-agent contract last offseason because they said he fit their safety position to a T. He could play both free and strong, he had the smarts and communication skills to set the secondary and he could slide into the slot against receivers when defensive coordinator Bill Davis wanted to stay in his base defense.

While having Jenkins in the slot as opposed to cornerback Brandon Boykin helped against the run, teams were effective throwing out of "11" personnel (three receivers) when the Eagles stayed in their base defense. Receiver Doug Baldwin caught three of four passes for 52 yards and a touchdown when singled up against Jenkins in the Seahawks' December win over the Eagles.

"I feel like they messed up the coverage if that happens," Baldwin joked. "In all seriousness, it doesn't affect me and my mind-set. I think that there's a lot of safeties out there that are just as good as [cornerbacks]."

Thomas is one, but there aren't many others who are just as effective helping against the run. Chancellor is better covering tight ends, but receivers hesitate going over the middle against Seattle's enforcer, a role his said he relishes.

Thomas was a first-round draft pick - yes, the Eagles passed on him in 2010 - so his success is not much of a surprise. Chancellor dropped to the fifth round in that same draft because some teams saw him as a linebacker. Carroll didn't.

"One thing Coach Carroll when he first called me . . . told me, 'All we want you to do is bring what you bring to the game and that's being physical,' " Chancellor said.

And Carroll made it work.