What was that about the Steelers defense again? They're too old, right?

The aged Steelers defense, with some youth infusion, finished the 2011 season with the league's best scoring defense, allowing just 14.2 points per game.

That's down from their league-best 14.5 points a game surrendered last year, when they were all a year younger.

The Steelers allowed just eight points a game over their last six contests (5-1), and their opponents only scored three touchdowns in that span - two from San Francisco in a Week 15 loss and one from Cincinnati in a Week 13 win.

And all of this was done with two of their best players, James Harrison and LaMarr Woodley, only playing three full games together, none of them over the last six weeks.

Bizarrely, it's also being done with just 14 takeaways, which ties New Orleans for the lowest mark in the NFL. The Saints allow 21.3 points a game, 13th best in the league.

Pittsburgh's -8 takeaway rate is the second-lowest among playoff teams, just in front of Denver's -11.

The Steelers didn't take the ball away, they just simply didn't allow teams to score. Unlike Steelers teams of the past, however, it was done mostly by their pass defense. They allowed just 5.6 yards a pass, the lowest in the NFL, and their 71.3 passer rating against is the third-lowest in the league.

In-season injuries and replacements forced several younger players into key roles. NT Steve McLendon and DE Ziggy Hood because mainstays on the defensive line due to injuries to Casey Hampton, Aaron Smith and Brett Keisel. Jason Worilds saw extensive playing time in the absence of Harrison and Woodley, and ILB Lawrence Timmons was moved to the outside for an extended period of time. CBs William Gay and Keenan Lewis moved ahead of Bryant McFadden as the season progressed as well.

With all the injuries and constant shifts in personnel, it's remarkable the Steelers were able to keep their opponents out of the end zone as often as they did. They allowed less than 10 first downs a game, and and only 34 plays of 20 yards or more.

Heading into the playoffs, and with a first round game against offensively-challenged Denver, the Steelers look to have both Harrison and Woodley playing again, and that could be a critical factor this post-season.