IRVING, Texas -- It sounds cliché, but stopping the run is vital for most NFL defenses.
The Dallas Cowboys have pretty much mastered that. Their run defense has allowed just three running backs to gain more than 100 yards in the past 20 games.
Two of them, the Baltimore Ravens' Le'Ron McClain and Willis McGahee, did it in the same game against the Cowboys back in 2008. Last season, the Cowboys were the only team not to allow a 100-yard rusher.
Over the next two weeks, starting Sunday against the Tennessee Titans, that run defense will get tested again.
Chris Johnson, who led the NFL in yards per carry last season at 5.2, comes to Cowboys Stadium. The following week, the Cowboys visit the Metrodome and the Minnesota Vikings' Adrian Peterson. And let's not forget about the run-oriented New York Giants or Maurice Jones-Drew and the Jacksonville Jaguars to finish out the month.
"As a linebacker, you definitely invite this type of game because it's like you against the other team, it's mano-a-mano," Cowboys inside linebacker Bradie James said. "We have to stop the run, that's what they do. [Tennessee is] not a big passing team, but they do pass the ball with [Johnson] and [Vince Young]. Those guys can kill you. At any point they can make a big play. You've got to have a lot of guys around the ball."
Since Wade Phillips took over as coach in 2007 and implemented his version of the 3-4 defense, the Cowboys have ranked in the top 10 twice in the past three seasons in run defense, and in 2010 they rank eighth.
In 2007, when the Cowboys held opponents to 94.6 yards per game, it marked the first time in three seasons that they hadn't allowed an average of 100 yards per game on the ground.
Phillips' scheme, or at least its success against the run, starts with nose tackle Jay Ratliff. Normal nose tackles get bottled up with a center and a guard, but Ratliff's quickness allows him to penetrate the backfield and disrupt run plays.
If a running back tries to move outside, the Cowboys position their outside linebackers -- DeMarcus Ware and Anthony Spencer -- out wide, therefore pushing ballcarries back inside or giving them little room to turn the corner.
Some of the Cowboys' best players are run stoppers in Marcus Spears and Igor Olshansky at end, and Spencer is stronger against the run than the pass. Ware, of course, is an All-Pro at nearly everything.
"When you have three big guys up front that usually take on two guys and four big linebackers who can run, that's what really makes us effective," Ware said. "We can run sideline-to-sideline probably better than any of the other teams in the league. Then we have me and Spencer on the edge."
And if a running back thinks he can outrun someone on the line of scrimmage, forget it. Ratliff's motor allows him to make plenty of tackles for loss and on the backside. Ware is also good at pursuit from the backside as running backs look to turn the corner.
"You've got to be technique sound," backup defensive tackle Stephen Bowen said. "Up front, we take pride in stopping the run and we want to make teams one-dimensional and we want them to pass, and that's when we get loose. But we know we can't do that if we don't stop the run. That's embedded in our brain."
Johnson has the 4.3 speed that makes catching him on the backside difficult. He's also good at making defenders miss in space, so open-field tackling is important in a game like this.
The other factor is Young. His speed forces defenses, especially at linebacker, to watch him in the passing game if he's flushed out of the pocket.
Keith Brooking and James have played at least 97 percent of the snaps in 2010, and there is a concern about wearing down later in the season. James and Brooking laugh when asked about getting tired. But this is the fastest running back/quarterback combination they may face all season.
"Any time, he can take off for like a 60- or 80-yarder," Young said of Johnson. "Sometimes he can grind it out and then he'll bust it later on in the game. But his presence does a whole lot to a lot of defensive coordinators, to know that you've got to keep an eye on him, knowing he can always break it any time or catch it or different things."
So far, the Cowboys' defense has done its job when it comes to the run game. If the Cowboys can get Young to throw the ball downfield, it could make things very easy for the home team.
But first, the Cowboys must stop the run. It's almost as big as getting a sack on third down.
"The main thing is we're just trying to get a win and move past this game," Ware said. "Playing against a run-savvy team, actually, that's what we like. We've got Marcus Spears and big guys up front, aggressive guys up front; that's what we like to do. We pride ourselves on stopping the run and this is going to be a good test."