Belichick's system cherishes veteran linebackers

PHOENIX -- In terms of financial outlay, the New England Patriots' biggest offseason addition wasn't wide receiver Randy Moss.

The real big spending was the signing of unrestricted free-agent linebacker Adalius Thomas to a five-year, $35.04 million contract, which included $20 million in bonuses for the eight-year veteran and two-time Pro Bowler.

The largesse of owner Robert Kraft in spiriting Thomas away from the Baltimore Ravens should not have been surprising, given the significant role that linebackers always have played in coach Bill Belichick's 3-4 defensive fronts.

In the Belichick chess match, linebackers always have been the most prominent pieces, and the New England coach has played a prominent role in developing the hybrid "edge" defender at the position.

"If you're a linebacker, then you want to play for [Belichick], because he does so much with the position," said New England outside linebacker Mike Vrabel, who earned his first Pro Bowl berth this season by notching 77 tackles and a career- and team-high 12 ½ sacks.

"He really asks a lot of the linebackers, but he also makes it fun, because he challenges you mentally and physically and puts you into position to make plays. He's very creative with the position."

And also very selective about who plays it for him.

It isn't by happenstance that all four of the New England starters are 30-somethings.

Thomas, at age 30 and having completed his eighth NFL season, is the toddler of the bunch. The starting quartet -- Thomas and Vrabel on the outside, and Junior Seau and Tedy Bruschi inside -- averages 33.8 years old, 12.3 seasons in the league, 176.3 appearances and 132.0 starting assignments. The four also have combined for eight Super Bowl appearances and 16 Pro Bowl berths. Each has made the trip to Hawaii at least once.

It clearly is an older group and one that collectively struggles at times to control offensive players in space, but the Patriots' linebackers are battle-tested and their aggregate football IQ is off the charts.

In order to play for Belichick, that's a must.

"I don't know that it's any more complex a defense than what I played in Baltimore, because some of the things that we did with the Ravens were really [sophisticated], too," Thomas said.

"But it's definitely a defense, and a position, where you better be a thinking man, a guy who plays as much with his head as his body. And you better come, and I mean every day, ready to work and play hard."

Things got a little harder for the New England linebacker contingent when nine-year veteran Rosevelt Colvin suffered a season-ending foot injury in late November after 11 games. The loss of Colvin precipitated the move of Thomas to outside linebacker and disrupted the three-man interior rotation that had been established. It meant that Seau, 39, and Bruschi, 34, had to log more snaps. The two elder statesmen have held up well, though, and the New England defense has not suffered any discernable slippage.

The position lacks depth, with the backups relatively untested, but the Patriots' linebackers remain the team's main instigators.

Vrabel comes hard off the edge, alternating between the strong and weak sides, and is the best overall sack threat. This is the sixth straight season in which a linebacker has led the Pats in sacks. Thomas is a terrific blitz/cover combination defender, a guy versatile enough to move out into the slot and cover tight ends and wide receivers.

Bruschi and Seau remain stout against the run. Both were key to the Pats' success in red-zone situations against the San Diego Chargers in the AFC championship game. Seau remains one of the game's great "guessers," a guy who occasionally will break with discipline and shoot the gap based on a hunch.

Chided Vrabel: "He's not playing too bad for an old [guy]."

Belichick doesn't mind age as long as players still are productive, and Seau has made big plays as the stakes have grown in the approach to the Super Bowl. A well-conditioned athlete, Seau also is a leader in the locker room, and he's got a rare cachet, a player whose influence cuts across racial and age lines.

There is a notable lack of youth among the regular contributors from scrimmage, and, while Belichick contends that is not necessarily by design, it's pretty obvious he prefers experience over youth at the position.

Before the injury to Colvin, each of the team's top five linebackers was a player added to the roster through free agency. The Patriots really have not developed a home-grown, full-time starter at the position during the tenures of Belichick and vice president of personnel Scott Pioli.

In fact, as critical as linebackers have been to Belichick, he rarely has used a high-round selection on one.

In their eight drafts with the Patriots franchise, Belichick and Pioli have invested just seven of 70 choices in linebackers, none of them taken any higher than the fifth round. Four of the seven were seventh-round selections. In his 13 seasons as a head coach, Belichick has used just 12 of 111 draft picks to choose linebackers. Not since he chose Craig Powell in the first round of the 1995 lottery, when he was the head coach of the Cleveland Browns, has Belichick selected a linebacker higher than the third round.

"It's just been more circumstance than anything else," Belichick said.

But some of his veteran linebackers aren't so sure.

"For this defense," Seau said, "it's a really [demanding] position. I think he really likes and appreciates having older guys."

Senior writer Len Pasquarelli covers the NFL for ESPN.com.