What they do doesn't necessarily show up on the stat sheet at the end of a game.
But ask any of their teammates or coaches who the key to any good 3-4 defense is and they'll immediately point to the nose tackles.
That's why it's no coincidence the Pittsburgh Steelers and San Diego Chargers have had two of the best run defenses in the league over the past few years. In Pittsburgh's Casey Hampton and San Diego's Jamal Williams, the two teams have perhaps the two best nose tackles in the NFL.
"I don't have any doubt that the two of them are at the very top," said San Diego head coach Marty Schottenheimer of Hampton and Williams. "I know one thing, you don't want to play against them if you don't have to. They are so physically dominant. Their ability to plug the whole middle up, it's remarkable. It turns other people loose as we know."
That's worked out well for both teams. Last season, San Diego had the NFL's toughest run defense, allowing 84.3 yards per game, while the Steelers were third at 86.0. Both teams have been even tougher this season, with the Chargers giving up 66.0 yards per game on the ground and Pittsburgh allowing 78.3.
When they meet Sunday night in San Diego, there doesn't figure to be a lot of running room for either team. And Hampton and Williams are a big reason for that.
"Those two guys are the best nose tackles in the league," said Steelers center Jeff Hartings, who works against Hampton all the time and will be faced with stopping Williams this week. "They both are very strong and they're also very good athletes. They're not just going to sit there. They can move. They can move even when you've got good position on them."
That's the thing that separates the 6-1, 325-pound Hampton and the 6-3, 345-pound Williams from many other players at their positions. Both are much more active than you'd expect a man of their size to be.
It's one of the things that makes them so difficult to defend. Instead of a guard helping the center out by chipping the nose tackle and then moving on to block a linebacker, teams working against Hampton and Williams are forced to keep a double team on those two players.
"You're going to double-team those guys anyway," said Hartings. "But if they force the center and the guard to stay on them because you don't get them pushed back, then the linebackers have a lot of freedom to run around."
One would think that working against Hampton in practice would give Hartings an advantage over many other centers, but that's not necessarily the case. While Hampton never misses a practice, he doesn't always go quite as hard at his teammates as he does in a game, when he often embarrasses an opposing center by driving him five yards into the backfield.
"Working against Casey in practice isn't like playing against Casey," said Hartings. "But what does help is that we face a lot of 3-4 defenses. We've played Baltimore for years and we've had a lot of battles with New England. So I think the experience of playing against the 3-4 team with a big nose tackle definitely helps."
As for those embarrassing moments that can happen working against a guy like Hampton or Williams, Hartings, who is a little undersized at 6-3, 295 pounds, said he knows how quickly they can make a center look like he's on skates being pushed into the backfield.
"I've never had the experience of playing against Casey, but playing against Jamal is the closest thing to it," he said. "You've got to get off the ball and hit him as fast as you can. Sometimes you miss a hand and when the hand gets high, he's going to push you back."
Dale Lolley appears courtesy of the Observer-Reporter.