With the hiring of Jack Bicknell, Jr. as the Steelers' new offensive line coach and his history with the zone blocking scheme, there has been a lot of chatter recently about the Steelers becoming a zone run team.
But what does it mean to be a zone run team? What are the basics of how the zone works? What types of players flourish in the scheme? And what would the scheme mean for us as it pertains to our current roster? This post attempts to clarify some of those questions.
What is a "zone" scheme of blocking?
There are two basic concepts that make up the zone scheme. These are the inside zone concept and the outside zone concept. For the sake of brevity, I'll confine this post to the inside zone.
Unlike man-blocking schemes, the inside zone play assigns blockers to an area. That area is the playside gap adjacent to their alignment. Gaps are labeled from the center on out. The gap between the center and guard is commonly called the A gap. The B gap is between the guard and tackle and the C gap is between the tackle and tight end.
Image created by Niners Nation
So, in a zone scheme, the center is stepping to the playside A gap and working through that area, blocking whomever is there. If there is a down lineman in the A gap, such as a shaded nose tackle, the center will block him. If not, the center will climb to the 2nd level to block the linebacker. Some teams call this a "covered-uncovered" rule, meaning if there is a down lineman in your playside gap you are covered and you block him.
If there is no down linemen in your playside gap you are uncovered and you climb through the gap to the linebacker level. Either way, everyone on the offensive line is stepping to their playside gap on the snap and following this progression. Some teams have their "covered" linemen handle first-level defenders one-on-one. This allows "uncovered" linemen to climb quickly to the 2nd level to get on the linebackers. Nothing makes life more miserable for a linebacker than a 315 pound guard in his face right away.
Other teams prefer to double team the first-level defender and push him to the linebacker. Defensive lineman like Vince Wilfork or our own Casey Hampton basically necessitate the double-team approach because few (if any) offensive linemen can handle them one-on-one.
When executing a double team, one of the offensive linemen will chip off and block the linebacker when that linebacker steps up and presses the hole. A common rule for zone linemen using the double team technique is "Four hands on the lineman, four eyes on the backer." This means that while both linemen should be pushing the defender at the first level, their eyes should be looking for the backer at the second level.
Quick backers like Lawrence Timmons can sometimes run clean through a hole because one of the blockers can't get off the double team in time. That's why a guy like Hampton is so valuable against zone offenses. By eating up two blockers at the line of scrimmage, he creates opportunities for run-throughs for his backers or at least keeps guards from getting onto them before they can begin to pursue the play.
Why do so many pro and college teams use the zone scheme?
There are two prominent reasons. First, because defenses have the advantage of being able to move around prior to the snap, it has become increasingly difficult for offenses to run schemes that prescribe their lineman to block a specific man. Defenses stem, slide and shift their fronts constantly in order to mess with the blocking rules of the offensive line. The zone game compensates for this.
Whether teams use a count system or the covered-uncovered rule, all the offensive line has to know at the snap is whether there is a defender in their playside gap. This allows zone teams to block any front at any given moment. Second, since everyone on the offensive line is stepping to the adjacent playside gap on the zone play, it creates what is called a "full-flow" read for the defense. There are no pullers, trappers, scoopers, etc.
A full-flow read gets the defense moving quickly because it indicates to defenders that the play is headed in that direction. If everyone (including the back) is stepping right, logically the play is headed right. This would seem to be a dead giveaway for the defense. However, teams have implemented the zone game to use the pursuit of the defense against itself.
In this example Behind The Steel Curtain ran after the Steelers' win over the Giants in Week 9, running back Isaac Redman cuts back on an inside zone run as the offensive line pushes to the left.
What makes for an effective offensive lineman in a zone scheme?
Quick offensive linemen tend to fare better in a zone scheme than do big road-graders. The zone scheme requires them to move their feet well, and if they can't get off the ball quickly or climb to the 2nd level to block a backer in space they're likely to struggle. This isn't to say a 340 pound monster can't succeed in it. Mike Iupati, the 49ers Pro Bowl guard, is listed at 335 and has thrived in the zone scheme. Traditionally, though, trimmer, more agile linemen (think New England's Logan Mankins or the Indy unit from a few years back) tend to flourish with the zone.
The zone scheme also requires great communication from the OL as a whole. Because blockers are often working together in "double and chip" techniques, they have to know who is going to stay on a down lineman and who is going to chip off to the backer. If that communication gets messed up, one of the defenders is turned free. Offensive linemen must also quickly diagnose whether they are covered or uncovered as the defense moves and shifts before the snap. A covered lineman might become uncovered a split second before the ball is snapped as the defender over him shifts a gap. In this instance he has to know that he no longer blocks that man but climbs to the backer instead. And the lineman next to him needs to know that he is now responsible for the defender who has shifted. Without good communication among the OL the zone scheme can be easily disrupted.
In another example from Behind The Steel Curtain, we see the Steelers' tackles, Max Starks and Marcus Gilbert, fail to maintain the continuity of the line for running back Jonathan Dwyer to have enough time to make a cut while moving forward.
Dwyer's cut isn't decisive, and the play ends up being a significant loss.
What makes for an effective back in a zone scheme?
Vision and burst are two essential ingredients. Good zone backs don't have to be burners but they have to be able to see a seam when it develops and then burst quickly through it before it closes. To allow those seams to develop, they also must have patience. Zone backs are often taught "Slow to the hole, fast through it." This is because holes are not pre-determined but develop as the defense flows to where they think the ball is headed. A back that is too fast usually buries himself in the backs of his linemen. A back with no burst, however, can't get through a crease once it develops. That's why guys like Rice, Arian Foster and Matt Forte are so good in the scheme. They are patient, have great vision and when they see a hole open they can get through it quickly. They're not the fastest guys in the world but they don't need to be because their acceleration and cutback ability are phenomenal. And if defenses stop flowing quickly to take away the cutback, they're fast enough to capture the edge on the outside zone play.
Part II will explore the Steelers current roster make-up and throw out a few options in terms of personnel to run this scheme.