The defensive line on a football team is made up of the biggest and strongest guys on the defense. They play the game of football in "the trenches," where they battle with offensive linemen play after play. How well they play in any given game will have a big impact on the outcome. Their primary focus is to wreak havoc on the offensive blocking and passing schemes. Over the years, defensive linemen have also increasingly been called on to drop in pass coverage as well, particularly in zone defense.
Which Positions are on the Defensive Line?
In a typical defensive scheme, there are two defensive ends and two defensive tackles. Some schemes call for a nose tackle or nose guard. In goalline situations, additional linemen may be brought in, or linebackers may move up to the line of scrimmage to stop the short run.
What Makes a Good Defensive Lineman?
Good defensive linemen are big, strong, and quick. They have to react to the snap of the ball, and get upfield to try to jam up the offensive blocking scheme. If it's a pass play, they'll use whatever moves they have in their toolbox to get to the quarterback and disrupt the throw. If they can disrupt the timing of the throw, or make the quarterback hesitate in making the throw, it's a success. If it's a run, they will play good gap defense, and make the tackle if the runner is in their gap. They have a thankless job, because on most plays they hold up a blocker or two and the linebacker makes the tackle. The linebacker gets his name called, and his picture in the paper, but credit is not often given to the linemen that moved guys out of the way, and disabled the offensive scheme.
The New Defensive Lineman
There has been a trend shift, however, with the visibility of guys like Jared Allen (Minnesota Vikings), and Ndamukong Suh. Suh was the first defensive lineman ever to win the Associated Press Player of the Year Award (2009), and was also a Heisman finalist, in addition to winning many other collegiate awards. These guys have increased the popularity of the trenches with their accomplishments and athleticism. This is great for the game of football, and great for aspiring players.
So the next time you're watching a football game, keep your eye on the trenches. See if you can tell how much of the game is affected by what happens there.