Below is an essential run play in any zone-blocking scheme. If you are interested in me diagramming a specific play or exhibiting fundamental differences between Greg Knapp's offense and Mike Holmgren's offense, like wide receiver splits, leave a comment and I'll make it the subject of a future post.
Oakland is pinned at its own five. The Raiders set 2 wide receivers, tight end, I-backs. The Chiefs set in a balanced 4-3.
Zach Miller motions in, crosses behind the center and then returns to a recessed position off right tackle. Strong safety Bernard Pollard moves up into the second level.
Snap.
Right tackle Cornell Green pulls hard left. Miller moves up to block Chiefs left defensive end Turk McBride. Miller is a Carlson-esque tight end and an asset in Knapp's system. Ronald Curry cuts across field looking for a Chief to engage. It's already clear, with Oakland's interior line bunching and blasting left the success of this plays hinges on Miller and left tackle Mario Henderson containing their respective assignments, McBride and right defensive end Tamba Hali, preventing them from shooting in and redirecting or tackling Darren McFadden.
From behind, the essence of this run is revealed.
Green cuts Tank Tyler. Center Jake Grove cuts middle linebacker Pat Thomas. Robert Gallery and Cooper Carlisle combo block Glenn Dorsey. The three interior linemen, right tackle Green and fullback Justin Griffith form a five man wedge in front of the slashing McFadden.
From the scrum a hole emerges Emmitt Smith could run through.
The Zone Stretch is not a play, but a family of plays or, more accurately, the opener for a set of possible runs. Zone blocking empowers linemen to adjust and pick their assignment in response to the defense. A stretch has a few fundamentals: Linemen block one direction, typically the direction of the run; a defensive lineman, typically a defensive tackle and typically the defensive tackle positioned to the side the run is directed, is double teamed; one of the two blockers doubling the defender walls off the defender while the other pulls into the second level. Other rules may be instituted on specific plays, but the elegance of a zone block is that blockers may "audible" their assignment on the go. It's so libertine and spontaneous one wonders how Tim Ruskell ever convinced Mike Holmgren into accepting it.