A Beginner's Guide to Zone: Covered and Uncovered Rules

One of the most popular methods for teaching inside zone is to teach it using "covered" and "uncovered" principles.  The was the style of zone that powered Tom Osborne's dominant Nebraska Cornhuskers rushing attacks of the 80s and 90s.

A lot of what got mistakenly referred to as triple option in Osborne's offense was anything but: he'd simply stretch the defense laterally with Outside Zone blocked double option plays (and a quick flash fake to the Fullback) to get the defense flowing hard, then gash them up the middle with a called Inside Zone dive to the Fullback when the Linebackers were overpursing to the outside.

There are various "flavors" to using covered and uncovered rules for your zone blockers, but the basic concept is as straightforward as it gets: if you're covered, you block that guy, but if you're uncovered you read the next defensive lineman to the play side as you work up to a linebacker.  However, like all things Zone, the devil is in the details.

The first issue that a coach who wants to use Covered and Uncovered rules as the basis for his scheme needs to define is "What is covered?"  It's surprisingly more nuanced than it looks at first glance.  Just saying "a defensive lineman on any part of your body" can lead to odd situations where you wind up trying to base block a stunting defender or wind up working away from the call and leave a hole for a Linebacker to run through and kill the zone.  It also fails to account for defenders parked in gaps or linebackers who walk up late.

My preference is to define "Covered" as when there is a defender shaded into any part of the Offensive Lineman's play side gap or head up on Offensive Lineman.  If we're referring to the play side guard, for example, this could be a 3 tech or a 4i or it could even be a 2 tech, since that 4 tech may likely pinch.  That means that "Uncovered" is everything else: nothing in the gap or head up on the offensive lineman.

On Inside Zone plays, the covered Offensive Lineman will simply base block the defender head up or in his play side gap.  He'll step with his head, hip, and foot to the inside to get position and drive block the defender straight back.  On Outside Zone plays, he will reach block the defender by stepping "big toe to pinkie toe" with his play side foot to the defender's outside, swinging his hips around, and driving him vertical with head, foot, and hip on the defender's outside.

The uncovered Offensive Lineman is where the magic really happens in the Zone and what truly makes zone blocking such a dynamic scheme up front.  As Bill Mountjoy (expert on the zone and pro-style offense) says "where there is no uncovered lineman, there is no zone."

The uncovered Offensive Lineman will take a "bucket step" (a drop step at a 45 degree angle with his play side foot) and work through his play side gap to get hip-to-hip with his play side teammate to overtake the defender.  This results in a combo block.  When the Uncovered Lineman successfully overtakes the defender, the Uncovered Offensive Lineman's technique will physically "wipe off" the Covered Offensive Lineman from his block to get to the second level

If the defender stunts away from the Uncovered Lineman across his teammate's face into the next gap over, the Uncovered Lineman simply works up to the second level and blocks a Linebacker while his teammate continues to base block the defender.

This is one of the simplest and most popular ways to teach zone, but like the Count System we discussed earlier in the series, it's not without its own pitfalls.  The first is defining what "head up" actually means--it needs to be narrowly defined as "a defender with his helmet between your feet" to avoid confusion over whether a defender is shaded backside or head up.

The other major issue is that, by itself, the covered and uncovered rules don't necessarily fully account for defensive post-snap movement or run throughs, though they handle this better than the Count System we discussed in the last post.  There is still some additional teaching necessary.

In fact, many zone teams combine both styles into a multi-layered set of rules to better account for the gray areas: the count clarifies which pair of Offensive Linemen will block which pairs of defenders while the Covered and Uncovered rules clarify what technique to use to get the job done.

However, as I've coached Zone and worked through some of the growing pains of doing it, I've found what I feel is a simpler way and better way to teach it, which I'll discuss in the next post.  Check back tomorrow for the third theory (and my personal favorite) style of Zone: the Track Zone!