Over the past few seasons, the spread offense has revolutionized college football.
Few teams operate two-back base offenses anymore, as many coaches always are looking to spread defenses with four- or five-wide receiver formations.
As a result, coaches also have changed their approach to recruiting.
Many college football teams no longer seek quarterbacks who can simply drop back and throw the football 50 yards down the field. Instead, many teams want quarterbacks who run as well as they throw in order to spread defenses even farther across the field.
More and more, college football teams also are looking for faster, slimmer players who can defend the spread attack. Coaches want 275-pound tackles who can stop the run and rush the passer. They want 250-pound ends who can sack the quarterback and drop into pass coverage.
Ends have become tackles. Linebackers have become ends. Safeties have become linebackers.
"You're always looking for a great pass-rusher on defense," NC State coach Tom O'Brien said. "With the speed of the game and the way it's opened up, it's important that you have somebody that can play in space and play on the edge and get up the field and create havoc."
Ironically, as the importance of defensive linemen has grown in college football, they have gotten smaller. Only four of the past 12 defensive linemen named to the Associated Press All-America team weighed more than 300 pounds. Pass-rushers built in the mold of former Virginia All-American Chris Long and South Florida's George Selvie have become a premium on the recruiting trail.
"It's the premier position at the next level in the NFL," said James Coley, Florida State's tight ends coach and recruiting coordinator. "You're seeing more of them in college. You see particular teams in college with a guy whose sole purpose is to come off the edge and get after the quarterback. It's a big deal for us, and it always has been."
Finding defensive linemen with the ability to stop the run and rush the pass isn't easy, though.
"Recruiting seems to go in cycles," said Bruce Chambers, Texas' tight ends coach and recruiting coordinator. "One year, it might be a really good year for linebackers, and the next year, it's wide receivers. But it always seems hard to find defensive linemen, and I'm not sure why."
Only 12 defensive linemen were ranked among the top 100 of the ESPN Top 150 last year, including three rated among the top 25 players in the country. End DaQuan Bowers of Bamberg, S.C., was ranked the No. 1 prospect in the country and signed with Clemson. Oklahoma signee R.J. Washington of Keller, Texas, was ranked No. 11, and LSU signee Chancey Aghayere of Garland, Texas, was No. 14.
"With offensive linemen being as big as they are, you've got to find guys who can physically match up with those guys up front," Chambers said. "He has to have the size, the strength and the quickness you look for in a defensive lineman. You can find them, but a lot of times they're big but don't have the quickness, or they're quick and don't have the size. When you can find one who has the size and the quickness and the grades, you can't pass him up."
Defensive linemen are at such a premium that many coaches look for prospects who played both football and basketball during high school. These athletes have spent most of their time playing in basketball and football games, rather than working to get bigger and stronger in strength programs.
"Our best guys have been guys who thought they were basketball players," O'Brien said. "They had the big wingspan and could run and have some length to them. You look at the type of guys that are doing both."
Before Mathias Kiwanuka was a star defensive end for O'Brien at Boston College, he played basketball at Cathedral High School in Indianapolis. Former Penn State All-American Tamba Hali played basketball while attending high school in Teaneck, N.J. Former Clemson All-American Gaines Adams concentrated on basketball at Cambridge Academy in Greenwood, S.C., because the school's gym was air-conditioned and much cooler than the football practice field.
"We get them in our strength program, and they're going to blossom," Coley said. "These kids in high school are playing sports non-stop. They play football and don't even get a winter break before they get into basketball season. Then they go to spring football, and then it's AAU basketball all summer. I love those basketball guys. They're big, long, athletic guys who can run, and they've got good eye-hand coordination and good feet."
As with nearly every position on the field, college football coaches look for guys who can run more than anything else.
"The overriding factor is speed," Tennessee offensive line coach Greg Adkins said. "You go across the country, and no matter what position you're looking for, you're always looking for guys who can run. Overall, your team speed is more important than anything else."
Especially when you're defending the spread offense.
Mark Schlabach covers college football and men's college basketball for ESPN.com. You can contact him at email@example.com.