Jared Allen went into last year's season finale against the Bears needing 4 1/2 sacks to break Michael Strahan's NFL single-season mark of 22 1/2.

Strahan survived as Allen had 3 1/2 sacks to finish with a team-record 22.

This year, Strahan's grip on the record doesn't look nearly has strong heading into the final two weeks of the season. J.J. Watt, a five-technique end in Houston's 3-4 front, and Aldon Smith, an outside linebacker in the 49ers' 3-4 front, are tied with 19 1/2 sacks.

Allen said he thinks the record will fall. At some point.

"I said it at the beginning of this year that I think 25 is a realistic number in the way this league is, especially with the 3-4 linebackers," Allen said. "You got Aldon Smith, who basically is a defensive end. You DeMarcus Ware, who basically is a defensive end with the athletic ability of a linebacker standing up and coming off the edge. Those are serious matchup problems. I think it's definitely attainable."

Watt already has more sacks than any 3-4 defensive end has had since sacks became an official stat in 1982.

"What J.J. Watt is doing is crazy from that five-technique position," Allen said. "That's like a once-in-a-lifetime, praise-God-that-thing-is-happening because you don't see that very often."

Not ready to name Foster No. 2: Allen was asked about Sunday's game having "the two best running backs in the league." Allen wasn't so sure about that one. He isn't ready to put Houston's Arian Foster No. 2 just yet.

"I would say Adrian [Peterson] is the best, without a doubt," Allen said. "But after what [Seattle's] Marshawn Lynch did to us [124 yards and a touchdown], hopefully Arian Foster doesn't do the same. Maybe we'll say [Arian] is third [best] right now."

Foster is fourth in the league in rushing with 1,250 yards. Lynch is No. 2 with 1,379 yards. Peterson is first with 1,812 yards.

More on Watt: Allen on Watt's strengths: "He doesn't try to get outside of himself. He does what he does. He has one move and he has a counter off of it. If he doesn't get there, he tries to affect the game in all facets. He bats the ball down and he can play right and left, so he's creating matchup problems, whether it's in the three-technique of the five-technique. The energy level and the effort he puts into his craft is high right now. His will not to be stopped. You have to have things go your way and have to have a couple of sacks fall into your arms. He's got everything going his way right now."

Allen said there are advantages to moving from side to side, "if you can do both."

"You're not stagnant," he said. "Teams can't game plan specifically for you. You can take advantage if one guard or one tackle is weaker than the other. I'm kind of old school in a way that, `Here I am. Left tackle is supposed to be your best tackle. Right end is supposed to be your best end. Let's see who is best.' This year, I've seemed to face left tackles, tight ends and running backs. I'd like to get just one left tackle. That would be nice.

"My theory is don't go putting me on the left side, where I'm not taking reps. You got to get used to doing things with opposite hands and opposite feet. So for me, I'm a little fish out of water on the left. Why handicap two people by putting someone over on the right. I know what I can do on the right and we have people who can do stuff on the left."