It will be at least two months before we know if the Buffalo Bills’ run defense is better than last year.

One thing is certain during the first week of training camp: It’s bigger.

The Bills’ hybrid defense has been aligned in a 3-4 front as its base formation, meaning there are three linemen with their hands on the ground and two outside linebackers standing up near the line.

One big difference from the 4-3 front run last year by coordinator Dave Wannstedt is the three down linemen all essentially are defensive tackles. Starting are 331-pound Marcell Dareus, 303-pound Kyle Williams and 301-pound Alex Carrington.

Carrington replaces retired Chris Kelsay, a 260-pounder, in the front seven.

Manny Lawson, at 240 pounds, is the prospective strong-side outside linebacker, taking a spot held last year by 240-pound Nigel Bradham.

Bradham still is in the starting lineup, at one inside backer position, more or less taking a spot held last year by 228-pound Nick Barnett.

It’s considerably more beef in the front seven than last year, when the Bills ranked second worst in the NFL against the run, allowing 146 yards a game.

Bradham is joined at inside linebacker by Kiko Alonso. Mario Williams is the other stand-up outside linebacker.

Jerry Hughes, a 254-pounder, might wind up playing some for Lawson in the base defense and probably will play for Lawson a lot in passing situations. Hughes has seen a good number of snaps with the starters so far. Jamie Blatnick, Marcus Dowtin and Kourtnei Brown are other unheralded candidates to contribute as edge rushers.

It’s important to note that the three-down, four-up, base front seven might only be on the field a third of the time because so many NFL teams run three- or four-receiver offenses.

The new base defense also is not a big change from an assignment standpoint for the down linemen. Most of the time there will be a down-lineman playing the “1 technique” or “shade” position, lined up on the outside shoulder of the center, not head-up over the center. This is where Dareus lined up a lot last year. There will be a down-lineman in the “3-technique” spot, lined up over the outside shoulder of a guard. This is where Kyle Williams lined up a lot last year. There will be a man in the “5 technique,” over the outside shoulder of a tackle.

“It’s not much of a difference for the interior guys,” said Torell Troup, who’s vying for a spot behind Dareus and Kyle Williams. “The only thing is we’ve got to attack more.”

The idea of trying to simply plug a gap is not what defensive coordinator Mike Pettine wants.

“We had to get out of that idea,” Troup said. “When they first introduced us to the defense that’s what we thought it was going to be. But they want us attacking, coming off the ball, hitting guys in the backfield and causing disruptions.”

The players also say they’re rotating among the different spots on the line a lot more than in the past.

“I’m everywhere, honestly – 5-technique, three, nose,” Carrington said. “I’d say it’s been fairly equal where I’ve lined up. You never know. It’s not just a 3-4. It’s multiple fronts, a very aggressive defense. Disruption is our M.O.”

The Bills tried to implement, a bigger, 3-4 hybrid front in 2010 when Chan Gailey took over as head coach and put George Edwards in charge of the defense.

Just like now, the down-linemen in 2010 were mostly playing one gap, not playing head-up on a blocker and trying to cover the gap on either side of them.

It didn’t work. The Bills were 32nd against the run in 2010, 24th overall in yards allowed. The problems were many that year. They had considerably less speed at inside linebacker, with a tandem of Paul Posluszny and Akin Ayodele, than the duo of Alonso and Bradham provide. They had no pass rush and didn’t blitz much. All of their edge rushers combined in 2010 managed just eight sacks. Mario Williams had 10.5 last season.

The Bills have plenty of questions to answer on defense – depth at edge rusher and pass coverage ability at linebacker among them. But size up front is not one of them.