The Chicago Bears use a zone-blocking run system under offensive coordinator Aaron Kromer. His schemes also incorporate a number of pulls and trap blocks. Chicago's two guards, Matt Slauson and Kyle Long, have been particularly effective coming across the line to kick out defenders and open holes for Matt Forte.
It's a strategy that takes advantage of defensive linemen and their desire to get into the backfield quickly. On a typical trap play, the play-side defensive tackle or defensive end goes unblocked by the blockers in front of him. Out of habit, the defender then flies into the backfield. At that point, he's blindsided by the pulling guard and the running back slips past him to the inside.
In essence, the offensive line lets the defensive lineman take himself out of the play, which sets him up for a downhill crack block by a guard with momentum. It's a sound strategy that, when executed properly, can create huge holes at the point of attack.
One play in last week's contest against the Minnesota Vikings clearly outlines the way in which Chicago can exploit up-field pressure in the run game. Let's break it down in the film room.
Here we have the Bears' offense backed up near their own goal line. Jay Cutler is under center with Forte alone in the backfield. The call is a draw play, which will require a cross-block by LT Jermon Bushrod and LG Matt Slauson – yet there's more to it than just a simple X block.
At the snap, you see Bushrod crashing down on the defensive tackle. Slauson also picks up the DT, which gives DE Jared Allen an open lane to the quarterback.
Bushrod blindsides the defensive tackle, knocking him off his feet. At the same time, Slauson is peeling off his block and has his eyes on Allen, who is making his way into the backfield.
With Allen already up the field, Slauson steps wide and helps the defender use his momentum to slide past the pocket. At this point, Allen has taken himself out of the play. Also notice that Bushrod's block sends the DT into the middle linebacker, killing two birds with one stone.
With Bushrod clearing out the inside, and Sluson kicking out on Allen, Forte has a huge lane through which to run.
The Pittsburgh Steelers' 3-4 defense allows them to dial up exotic blitz packages, sending any of their four linebackers into the backfield from any point on the field. And when Pittsburgh linebackers blitz, they come quickly and violently. If the Bears can identify the pressure pre-snap, these types of trap plays could be extremely effective on Sunday.
Jeremy Stoltz is Publisher of BearReport.com and a member of the Pro Football Writers of America. He is in his third season covering the Chicago Bears full time. Follow Bear Report on Twitter and discuss this topic on our message boards. To become a subscriber to the Bear Report Web site or magazine, click here.