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Shifty defensive tackles Jamaal Anderson, left, and Jonathan Babineaux, right, are the moving targets at the heart of Atlanta's defense. (AP Photo/John Bazemore)

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At first glance, the Falcons defense looks vulnerable to a power rushing attack. Look at their line and linebackers:

• DE Kroy Biermann - 260 lbs.
  
• DT Jonathan Babineaux - 296 lbs.
• DT Jamaal Anderson - 289 lbs.
• DE John Abraham - 263 lbs.
• SOLB Stephen Nicholas - 230 lbs.
• MLB Curtis Lofton - 242 lbs.
• WOLB Mike Peterson - 233 lbs.

Teams with big lines and backs look at these runs and figure they'll just ram the ball down the Falcons' throats. The Falcons success in scoring -- their 15.4 points allowed per game ranks fourth overall, just behind New Engand -- shows they can shackle an opponent when it matters. 

Their success demonstrates the rock/paper/scissors nature of football. The Falcons may be light, but they're also quick, and they use their speed to outflank opposing lines, rather than trying to outslug them.  They Falcons scheme works because they never present static targets.

Falcons HC and defensive architect Mike Smith knows that his line will get pummeled if he lines them head up over bigger opposing linemen and has them try to control dual gaps.  Not only does Smith put them in a one-gap scheme, where the Falcons linemen set up in gaps or shaded over a linemen's shoulder, but he calls an abudance of slants for them. 

The linemen are given presnap responsibilities that make them hard to hit.  A favorite tactic is a weakside slant, which worked very well against the Bears.  The Falcons line up much of the time in an overshifted 4-3 front, where strong outside linebacker Stephen Nicholas lines head up over the tight end and the line also puts three of its four linemen over the center or linemen on the strong side. 

The overshift gives the appearance that it lacks bulk to the weakside.  The weakside DT is shaded just outside the center's shoulder. The weakside end, usually John Abraham, lines up in the gap wide of the weakside tackle.  The middle linebacker and weakside backer Mike Peterson are playing four to five yards off the line of scrimmage, where they can identify the play and flow to the ball.

Chicago saw this and called a lot of weakside isolation and stretch plays -- and was stuffed.  That's because the Falcons had their linemen attacking the gaps towards that weakside.  The tackles are already in gaps which require the offensive linemen to reach block, but if they get aggressive slants at the snap, they can get into the gaps and across the line before the Bears linemen could react.  On many plays, the Falcons, especially DTs Jonathan Babineaux and Jamaal Anderson, were waiting for Bears runners at the point of attack.

Slants can disrupt power running attacks, but they also carry an element of risk.  If the Falcons coaches call their slants correctly, they're the equivalent of paper to the opponenents' rock. They surround and envelop their bigger, bulkier foes. On the other hand, if the Falcons call a play to one side of the line, and the opponent calls a toss or a counter the other way, they play the scissors to that rock; they are outflanked, outnumbered and crushed -- big plays ensue.

Atlanta has no choice.  They're smaller, so they have to gamble, and hope their safeties can close and make tackles when they call incorrectly. 

This week, they're also facing a different type of rock in the Dallas' line.  As I've argued before, the Cowboys linemen may be one of the girthiest, heaviest groups in the NFL, but they're not a traditional power offense.  They excel at draws and counters and block isolations and off-tackles far less effectively.  They are, in fact, a big version of a small line.  Their bread and butter plays are the type of runs which can hurt the Falcons the most.

Don't be surprised if Jason Garrett's first two or three counter or draw calls are stuffed, if the Falcons anticipate and slant towards them effectively.  If Garrett sticks with them, odds are that he'll catch Atlanta going the wrong way.  Think of last year's Bengals game in Texas Stadium, Dallas' best running game of the season.  Mike Zimmer brought a very similar, smaller, shifty line into the game and called a lot of slants towards the strong side, where Jason Witten lined up.

Garrett repeatedly beat them running Marion Barber on the bend counter to the weakside and gashed them on a 4th and 2 where the Bengals sold out inside and Felix Jones ran a toss play around them for a score. 

The run plays could likely be feast or famine calls. If the Falcons win most of the calls, the Dallas runners will get stuffed a lot at the line.  If Garrett gets into a rhythm, we could see a Cincy replay, where the Dallas runners are going 12 to 18 yards over and over again.

It's important for Dallas to win their share of these draw and counter calls, because Atlanta likes to play cover two in coverage.  They like to get the offense into second-and-longs and third-and-longs, where they can play the standard four short, three deep zone, with the safeties rotating to the outer thirds and middle linebacker Curtis Lofton dropping into the deep middle. 

This scheme can be very effective and denying the deep throws Tony Romo prefers and rewards quarterbacks who are accurate and who are willing to take the shorter throws to tight ends and backs.  It can be lethal to quarterbacks who lack patience and try to beat the zones with their arms.  Think of Dallas 28-27 comeback win versus Detroit in '07, where Romo threw sixteen completions to Witten, for a positive example of beating a cover two.  Think of Dallas' heart-stopping 25-24 win over Buffalo that same year for a negative example;  Romo forced a lot of red zone throws that evening and was picked off five times.

The lead draw has been Dallas' fundamental running play this year, and it will be more vital than ever tomorrow.  If the Cowboys' guards and center can control Babineaux, Lofton and Anderson, and get Romo into second-and-6s or less, Lofton will have to honor the run on play action passes, and the middle will be wide open for tight end seams, square ins, skinny posts and posts by the wide receivers.  If Atlanta wins the early duels, and the situations are 3rds and 8s, Lofton can drop and Romo will have a far more frustrating day.

The hype all week has centered on the Dallas wide receivers and it never floats far from Romo.  Keep and eye on Kyle Kosier, Andre Gurode, Leonard Davis and whomever lines up at fullback for the Cowboys.  They will determine whether Dallas is crushing the slanting Falcons blades, or being swallowed up by a giant Atlanta sheet of paper.

Jason Garrett and Tony Romo will be as smart tomorrow as the interior blockers let them be.