DEFENSES ARE BACK TO THE 3-4 PATRIOTS' SUCCESS DRIVES ITS POPULARITY.

Byline: Billy Witz Staff Writer

Bill Arnsbarger was in a bind. Early in the Miami Dolphins' training camp in 1971, starting defensive end Jim Riley was injured and Arnsbarger, the team's defensive coordinator, wasn't happy with the replacements.

So a little more than two weeks before the season opener, he persuaded coach Don Shula to trade for Bob Matheson, a linebacker that Cleveland had tried to convert into a defensive end. But after 10 days of practice, Matheson struggled too.

``Suddenly, it dawned on me he'd be a lot better standing up,'' Arnsbarger said. ``I talked to Don and it was fine with him, so we tried it.''

Thus the 3-4 defense was born.

Once named the ``53 Defense,'' after Matheson's uniform number, the alignment that uses three down linemen and four linebackers is making a comeback in the NFL. Five teams have switched to the scheme this season from the more traditional 4-3 (four linemen, three linebackers) - the 49ers, Dolphins, Cowboys, Browns and Broncos.

The 3-4's resurgence, like most trends in the NFL, is a form of follow the leader.

As recently as 2001, the Steelers were the only team employing the 3-4 as a base defense, but they led the NFL in total defense. The Patriots have won their last two Super Bowls using the 3-4 as their primary defense.

Also feeding the change are new head coaches, Romeo Crennel in Cleveland and Mike Nolan in San Francisco, who made their reputations as defensive coordinators coaching the 3-4 in New England and Baltimore, respectively. In all, about a dozen teams will be using the 3-4 in some form.

There are several advantages to using the 3-4:

--It's easier to find outside linebackers who can rush the passer than it is to find quality defensive linemen. Also, given salary-cap constraints, they're cheaper.

--It affords a defense more versatility since the fourth pass rusher can come from several different places, keeping the offense guessing.

--In zone blitzes, popularized by the Steelers, it allows the defense to drop a lineman into coverage instead of a linebacker.

``Most of the offenses now, they really call two plays and theyrun to what the weak side is, where there are fewer players,'' said Arnsbarger, who retired after coaching the Chargers defense during the run to the Super Bowl in 1994.

``The 3-4 gives you more balance with the nose tackle lined up on the center and three men on each side of the ball. It gives the quarterback a more balanced look and with good disguise, a little more hesitation on what the call should be.''

For example, with Willie McGinest, a 270-pound linebacker who can also play with his hand down, the Patriots surprised Philadelphia in the Super Bowl by staying in a 4-3 look the entire game. There are two keys to the defense working effectively: A strong, sturdy nose tackle who can defend the gaps on both sides of the center and an outside linebacker who can rush the passer. The ends in the 3-4, who are lined up on the offensive tackle rather than outside him, also must be sturdier, two-gap defenders.

As a result, changing the defense isn't as simple as adding a linebacker and subtracting a lineman. It often requires wholesale changes.

The Chargers made the transition look seamless last season. After allowing 441 points in 2003, defensive coordinator Wade Phillips was brought in, the draft and free agency were used to acquire several key pieces and the Chargers allowed just 313 points - 11th in the NFL. Dallas is hoping for a similar turnaround this year. The Cowboys led the NFL in total defense two years ago in Bill Parcells' first season, but his quick and small unit was exposed last year, falling to 16th overall.

Dallas signed free-agent nose tackle Jason Ferguson to anchor the line and used its first three draft picks this year, including two first-rounders, to select pass rusher DeMarcus Ware, end Marcus Spears and linebacker Kevin Burnett.

Cowboys defensive coordinator Mike Zimmer has taken a crash course on the 3-4 and some of Parcells' former players who played the 3-4 with the Giants, including linebacker Carl Banks and nose tackle Jim Burt, spent a week at Dallas' training camp in Oxnard working with players.

``The nature of this defensive is aggression,'' Banks said. ``The 3-4 is one of the best things that can happen to you if you're a good athlete because if you get the little things down, they just turn you loose.''

Still, Parcells has reservations.

``Burnett and Ware are just chasing cars right now,'' he said during training camp, having already lost Spears for several weeks with a knee sprain.

Later, he added: ``I don't know how much of this stuff we're going to end up doing. At the end of the day as a head coach, you want to have your best people playing the majority of the time.''

That's an idea that hasn't changed much since Arnsbarger had Matheson play with his hands off the ground.

``Usually running backs blocked linebackers, but when they couldn't teams started to slide the protection that way and use a tackle on (Matheson),'' Arnsbarger said. ``That's when we came up with the thought of blitzing one of the middle linebackers. It gave us a lot of flexibility.''

The Dolphins had so much success with their experiment that by the next season they played the 3-4 all the time.

It turned out to be just like everything else in that undefeated season - a perfect fit.

Billy Witz, [phone]

billy.witz(at)dailynews.com

CAPTION(S):

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Photo:

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Box:

(1) 3-4 OR 4-3?

(2) DYNAMIC DUO

(3) THE NICK OF TIME