Could 4-3 defense be keeping Eagles out of the Super Bowl?

DALLAS - Dom Capers thinks the Eagles could successfully transition into a 3-4 defense.

OK, the Green Bay Packers' defensive coordinator - one of the brightest minds behind the 3-4 - wasn't speaking specifically about the Eagles.

Capers actually addressed a general question a day before the Eagles named Juan Castillo their defensive coordinator and reaffirmed their commitment to the 4-3.

But the premise is one that deserves serious consideration, as a pair of 3-4 defenses from the Packers and Pittsburgh Steelers prepare to play Super Bowl XLV.

Pittsburgh has long employed the odd-even seven-man front, but Green Bay switched only last season. So the Packers' successful changeover invites the question: If they can do it, why can't other 4-3 teams (such as the Eagles)?

"I think you can," Capers said. "It's a combination. You've got to have good coaches. You've got to have the ability to adapt your system to the talent that's there at the time. You aren't going to have all the pieces in place."

There are plenty of reasons against changing to the 3-4 alignment, and the Packers certainly could have fallen back on those age-old arguments after they finished 6-10 in 2008. The most obvious one is that they didn't have the right personnel.

When Capers was hired a few weeks after the season, it was assumed that Green Bay would transition to his 3-4 defense. But it wasn't that easy. Head coach Mike McCarthy wanted to move to a 3-4, but like the Eagles, the Packers were missing necessary pieces - a nose tackle and a pass-rushing outside linebacker.

"We had to do some maneuvering," Packers safeties coach Darren Perry said. "And some days, we went back and forth a little bit in terms of how we're going to make it work. But, in the end, we were able to draft a couple of guys."

In the 2009 draft, Green Bay took nose tackle B.J. Raji with the ninth pick overall and linebacker Clay Matthews 17 picks later in the first round. After promising rookie seasons, both blossomed into two of the best at their positions, with Matthews finishing second in voting for NFL defensive player of the year.

The Packers' defense, meanwhile, improved dramatically after finishing near the bottom in nearly every statistical category in 2008. This past season, the defense was ninth overall, sixth in takeaways, and second in points allowed.

Ranked ahead of them in points surrendered were the Steelers. It was no coincidence that Capers and Pittsburgh coordinator Dick LeBeau helmed the top two defenses. The two gurus are former colleagues and friends and basically installed the Steelers' defense as it is now in 1992, when Capers was the coordinator and LeBeau was his secondary coach.

LeBeau took over for Capers when the latter left to take the head-coaching job with the Carolina Panthers. But LeBeau kept the system intact and took it with him to Cincinnati and then back to Pittsburgh.

"I think the advantage of the 3-4 is that you're looking for [linebackers] that are in the 230- to 260-pound range that have pass-rushing ability and can get out in space and cover some ground," LeBeau said. "When you have the 4-3 line, that fourth guy has got to be a 300-pounder. It's easier to find gifted 250-pounders than it is to find a gifted 300-pounder."

Although the idea of the Eagles' moving to a 3-4 is now a moot point, they could have made the change last off-season. They had several high draft picks and could have used them to remake the defense. They did use their selections on defensive players, taking end Brandon Graham and safety Nate Allen.

But coach Andy Reid and defensive coordinator Sean McDermott were intent on staying with the 4-3, which had been in place since Reid took over 12 years earlier and Jim Johnson was his defensive coordinator.

As the story goes, Reid kept Johnson and his 4-3 defense in mind when the Colts' defense - under Johnson - gave the Packers fits when Reid was the quarterbacks coach. Reid is still married to the scheme, even though almost half of the league now uses a 3-4 and his own offenses have struggled against it.

One reason for the Eagles' difficulties against the 3-4 could be that they can't simulate the look in practice. The Super Bowl should be quite the chess match because of the similarities between the Packers' and Steelers' defenses.

The NFL, after all, is a copycat league.

"When I first came into the business, it was all 4-3 and then we had a great advantage running the 3-4 because we were looking for different type of talent," Capers said. "Then it went to 3-4, then back to 4-3, and you're seeing a lot more 3-4 teams now. . . . The more prevalent things become, I think sometimes they become less effective, so you have to stay ahead of the curve."