There's a reason the Longhorns took Garland linebacker Tevin Jackson early in the 2010 recruiting process - he was the linebacker in the state of Texas with the best combination of size, speed, and striking ability in a deep linebacker class. In football, there will always be a need for linebackers with Jackson's skill set.
The other top linebackers, Corey Nelson and Aaron Benson, are both smaller, faster linebackers more highly rated than Jackson (for now, at least), with Nelson in particular looking physically more like a safety than a linebacker as a junior.
Is that a problem? Should Nelson or Benson be punished for not fitting cleanly into the traditional stereotype of their positions? In a word - no. Throw out the old prototype of big linebackers with two-gap responsibility asked to take on fullbacks in the hole - there's a new sheriff (or pirate, if you prefer) in town who likes playing in the wide-open places on the field.
The days of three linebackers on the field at the same time in the Big 12 are dead for the moment. Mark Mangino said so explicitly at the beginning of Kansas spring practice:
Probably 80 percent of the time, we're playing with two linebackers and an extra safety. What we feel like is we're going to have a guy who's a third linebacker, but he's mainly going to be a safety type-of-guy that can play in space.
It's a big change for a Kansas team that was known for having the type of big, slow linebackers that epitomized an era now fading into the past.
It's a necessary adjustment when facing offenses playing three or more receivers, as offenses can simply key on the number of linebackers and run against a 4-2 front or pass against a 4-3 front. The spread linebacker/safety hybrid keeps the defense from calling plays simply based on the defensive formation.
The other adjustment comes in the pre-snap depth of the linebackers against the spread. Colorado linebackers coach Brian Cabral, a fixture at the school since CU's Big 8 days, has been at the forefront of adjustments to combat the spread. Before there was spread linebacker extraordinaire Travis Lewis at Oklahoma, there was Jordan Dizon at Colorado - a smaller linebacker, but fast enough to play in space dropping into coverage or defending the run game from sideline to sideline. The days of 240-pound linebackers are mostly gone. Since few teams run the I formation, linebackers don't have to physically match up against fullbacks, now an anachronism; instead, they have to navigate through traffic pursuing plays sideways, as many one-back spread teams run a zone-blocking scheme, infamous in Texas circles for only moving horizontally.
Cabral lines up his ‘backers six or seven yards off the line of scrimmage, one or two yards farther back than most defensive coaches. The adjustment forces lineman in the zone scheme to cover more ground before they can attempt to block a linebacker, who is smaller, faster, and more elusive than the hole-plugging, plodding middle linebackers of former days. As dedfischer points out:
Since running is one thing they typically do well, Cabral will ask his guys to hang tight in the middle of the field until the play crosses their face, which allows them to play optimal inside-out football at linebacker.
Having more time to read and react keeps the linebackers from biting on play-action passes or misdirection running plays like counters or reverses, taking away the constraint plays offenses use against over-aggressive or over-pursuing defenses.
One element that dedfischer doesn't mention in his otherwise excellent post is that the alignment depth of the linebackers also allows another step or two when matched up against a tight end or receiver in the slot, helping cover up any deficiencies in quickly getting into their backpedal or a lack of hip flexibility in turning and running, though both of those traits are almost necessary for a spread linebacker in the same way that they are of tantamount importance for safeties and cornerbacks.
In that way, spread linebackers are often essentially over-sized safeties - OU's Roy Williams, a biscuit short of a linebacker in the NFL for the last several years, would now be a spread linebacker in college. He can't cover NFL receivers, but he probably could have handled college tight ends. Former Missouri safety William Moore is another example - a big, physical safety capable of playing the hybrid safety/linebacker role.
Perhaps the best example, however, of the new spread linebacker is OU's Travis Lewis. A 6-2, 230-pound linebacker with the speed of a safety (Rivals lists his 40 time as 4.34), Lewis racked up 19 tackles against Texas in 2008, ranging from sideline-to-sideline and nearly single-handedly stopping the Longhorn running game. It wasn't until late in the game when a Texas offensive lineman finally got to the second level and blocked Lewis that the Longhorns were able to break a big run, in this case Chris Ogbonnaya's game-sealing rush. A player who would have lined up at safety in another era, Lewis isn't a player capable of taking on and shedding offensive lineman, but his incredible quickness advantage keeps lineman from getting their hands on him the great majority of the time.
At Texas, the closest player to a pure spread linebacker the Longhorns have is 2009 commit Patrick Nkwopara, the undersized Nigerian with great speed. Perhaps the first player to receive the official stamp of approval from Will Muschamp, Nkwopara is also a guy who needs to play in space, of which there is plenty when attempting to defend Big 12 offenses, while providing the flexibility to keep Muschamp from having to make the choice about playing with three linebackers or going to a nickel defense.