Finding the big guys on defense is getting tougher.
Jim Haslett found out how much tougher during his first days as the St. Louis Rams' defensive coordinator. Haslett was introducing himself to players and scanning the room for powerful linebackers when he eventually ran across a keeper. The coach moved in to make acquaintances.
"I'm Jim Haslett," the coach said, extending a hand.
"I'm Steven Jackson," the Rams' running back replied.
Good talk, coach.
Jackson stands 6-foot-2. He is so impressively built that his listed weight, 231 pounds, seems inadequate. But the typical 4-3 linebacker isn't much heavier these days, averaging fewer than 240 pounds for those projected to start for teams around the league this season. The position continued to shed weight when Philadelphia released 262-pounder Jeremiah Trotter on Aug. 21.
"Teams have gotten away from those big backers because there's more emphasis on speed and blitzing and coverage and not taking on blockers," said an NFC general manager whose team will not pursue the Eagles' 30-year-old former defensive leader. "Size is only a plus if you are athletic."
Age and injuries make every NFL player a liability if he hangs around long enough. Trotter's replacement in the Eagles' lineup, Omar Gaither, is seven years younger and listed at 28 pounds lighter.
The weight difference is more than coincidence. The percentage of starting 4-3 linebackers weighing fewer than 236 pounds has doubled to greater than 40 since early in the 2000 season, based on listed weights.
An examination of NFL gamebooks from 2000 showed five starting 4-3 linebackers lighter than 230 pounds, based on weights available through the league's Web site. That figure has grown to nine using projected lineups for this season, even though fewer teams are running the 4-3. In 2000, teams listed a dozen 4-3 starters between 230 and 235 pounds. Projections show 19 this season.
Denver's projected starting linebackers average a league-low 231 pounds. Tennessee and Detroit average 231.7 pounds per starter at the position, followed by Buffalo and Seattle at 234.
The San Francisco 49ers switched to a 3-4 under coach Mike Nolan, but in 2001 the team drafted Jamie Winborn specifically to keep pace with the Rams' fleet offensive personnel. The league lists Winborn at 242 pounds, but he was closer to 220 back then.
"At times he was 218, 215, 212 pounds," said former 49ers defensive coordinator Jim Mora, now the secondary coach with the Seattle Seahawks. "But we had to do that for the speed, to match up with Marshall Faulk."
Projections for this season show 20 starting 4-3 linebackers weighing at least 245 pounds. That's down from 41 in early 2000, despite fewer 4-3 schemes.
A comparison of Pro Bowl rosters shows 4-3 linebackers declined in average weight from roughly 248 pounds to 240 since 2001. The average weights declined slightly every season during that span, except for 2004.
While 3-4 defenses have proliferated, taking with them bigger linebackers, the league's 4-3 linebackers are all about speed -- for good reason.
Fewer offenses lean heavily on powerful fullbacks. Defenses are less likely to need bruising linebackers to combat them.
Athletic tight ends are becoming more common. Heavier linebackers have a harder time covering them.
Teams are more likely to run and pass from spread formations on first and second downs. Most linebackers weighing 250 pounds have a harder time matching up.
"If you've got a couple of big defensive tackles who can pick up blocks, you can free up those [small] linebackers," Mora said. "Denver is a great example. They put a premium on speed at linebacker."
Coaches still talk about running the ball and stopping the run, as they should, but the smart ones know winning teams are more likely to excel in a range of offensive stats, notably yards per pass attempt.
Trotter was long a mainstay of the Eagles' defense. He was a four-time Pro Bowl choice and respected in the locker room. But he was also increasingly a situational run stuffer, and coaches preferred Gaither's potential.
If Trotter fails to resurface as a starter -- he reached a one-year deal with Tampa Bay on Monday -- the league could be down to eight starting 4-3 linebackers listed at 250 or heavier.
The projected list includes the Giants' Mathias Kiwanuka (265), the Eagles' Chris Gocong (263), Oakland's Sam Williams (260), Cincinnati's Ahmad Brooks (259), Chicago's Brian Urlacher (258), Kansas City's Napoleon Harris (255), the Giants' Kawika Mitchell (253) and New Orleans' Scott Fujita (250).
They are exceptions. More 4-3 linebackers are looking like the running backs they get paid to tackle. Jim Haslett can vouch for that.
Mike Sando cover the NFL for ESPN.com.