Chalk Talk: the Defensive Tackle

The Bears were hurt badly last season when safety Mike Brown went own with his foot injury, but losing defensive tackle Tommie Harris was even more catastrophic. Harris just might be the best in the NFL at his position. Correspondent Jeremy Stoltz breaks down the different kinds of defensive tackles and what their responsibilities are in both the 4-3 and 3-4 philosophy.

With NFL Commissioner Roger Goodell's recent decision to suspend the Bears' Tank Johnson for half a season – or six weeks on good behavior – Chicago's defensive tackle position has been stretched thin. With the offseason losses of Alfonso Boone and Ian Scott, the Bears are hoping that Dusty Dvoracek, last year's third-round draft pick, or offseason acquisition Anthony Adams can keep some of the pressure off two-time Pro Bowler Tommie Harris. If he's healthy, that is.

"I'm right on schedule, ahead of schedule," Harris says. "But we're just taking time. We have nothing but time right now."

Chicago's coaching staff is looking to spend much of that time developing an effective defensive tackle rotation without Johnson. Says Harris, "It'll be difficult, but the same way they played without me, we have to learn how to play [without Johnson]. Lovie will set it up right. He'll have the right guys in the right positions."

In order to know which tackle to play and in what situation, coaches must utilize their players' most advantageous techniques and gap responsibilities. Techniques and gaps describe where a defensive tackle is positioned along the line of scrimmage, his post-snap actions, and what type of lineman he is.

Defensive tackles are normally referred to as 1-technique or 3-technique linemen. The term "technique" is misleading though, as it refers not to a player's actual technique but where they line up at the start of a play. The defensive side of the line of scrimmage is divided into numbers. Each number corresponds with the placement of the offensive linemen. Directly in front of the center is the ‘0' position, or 0-technique. Between the center and guard is the 1-technique, across from the guard is the 2-technique, and between the guard and tackle is the 3-technique. These numbers continue numerically along the line of scrimmage, but for our purposes we will discuss only the 0-3 techniques.

A 1-technique tackle is normally referred to as a nose tackle. He lines up in front of the center, often "shading" or sliding his hips to one of the center's shoulders. Because they are double teamed by the guard and center on nearly every play, nose tackles are normally big, strong, and stout but less athletic. Alternatively, a 3-technique lineman, who lines up between the guard and tackle, is usually lighter and quicker at the point of attack. They are asked to shoot their gap and pierce the middle of the offensive line.'s pre-draft analysis of this year's 10th-overall draft pick, Amobi Okoye – one of only two DTs taken in the first round – states that he is "A developing player with great upside. Offers potential as a 3-technique lineman." This analysis explains that Okoye's body size and athletic ability should allow him to excel at disrupting the offensive line by penetrating the space between the guard and tackle, not by challenging massive offensive linemen head on.

If Okoye is smart, he will watch copious amounts of game tape of the Bears' defensive line. As most football fans are aware, Chicago's defensive front has one of the premiere 3-technique tackles in the NFL in Harris. Says Johnson, "Tommie is the best 3-technique in the league." A healthy Harris now looks for support from Dvoracek, another swift tackle from Oklahoma, and Adams, a converted 1-technique lineman.

Lisa Blumenfeld/Getty Images

"Whatever they need, I can do it," Adams says. "[But] nose tackle is more natural for me."

Defensive tackles are also differentiated by their gap responsibilities. Between each offensive lineman is a gap, allocated by the letters A, B, and C. The A gap is between the center and guard, the B gap is between guard and tackle, and the C gap is outside the tackle. Defensive linemen are referred to as either a 1-gap or 2-gap lineman. Like the numbered techniques, gap assignments often imply the type of player within the system.

A 1-gap tackle is asked to contain a single gap, normally A or B. He must clog up his gap and tackle any ball-carriers who come his way or use that gap to get to the quarterback. His job is to continuously attack, hoping to break through the line and disrupt the offense. For these reasons, a 1-gap lineman is usually smaller and very quick.

Comparatively, 2-gap defenders are responsible for two holes. They must tie up offensive linemen and react to the play as it develops. Most 2-gap linemen tend to be larger, Ted Washington-type players who eat up space and do not allow the offensive linemen to reach the linebackers. 2-gap tackles are normally found in a 3-4 scheme, where linebackers are asked to make most of the plays, while 1-gap defenders are more common to the 4-3 defense. As a result, any team that chooses to switch its defensive philosophy from a 3-4 to a 4-3, or vice versa, must also change the personnel of its defensive linemen.

When Harris went down with a season-ending hamstring injury last season, the NFL community witnessed how valuable a strong pass-rushing defensive tackle is to Lovie Smith's Cover 2 system. Harris is a 3-technique, 1-gap lineman who, in just three seasons, is considered the top player under those labels. How does he feel about being the best at his position?

"I think I train hard enough to receive that as a compliment," he said this week. "But I'm not satisfied. I'm not finished. We'll just see where it goes from there."

If he stays healthy, that could mean a return trip to the Super Bowl.

Jeremy Stoltz is a graduate of the Columbia College Story Workshop program in Chicago. He is a regular contributor to Bear Report and

Jeremy Stoltz's Chalk Talk Archive
06/07/2007 - Shotgun
05/31/2007 - Run-and-Shoot
05/24/2007 - 46 Defense
05/17/2007 - Screen Pass
05/10/2007 - Draw Play
05/03/2007 - West Coast Offense (Part II)
04/26/2007 - West Coast Offense (Part I)
04/19/2007 - Zone Blitz
04/12/2007 - I-Formation
04/05/2007 - Zone Blocking
03/29/2007 - Cover 2
03/22/2007 - Counter Trey

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