There appears to be some confusion around here about zone blocking, how it’s implemented at various levels and in various programs, and the experience players may have with it. I’m going to try to clear up some of that. Most of my knowledge of Zone Blocking comes from watching hours of Alex Gibbs, so I’m much more familiar with Outside Zone techniques where the back aims to bounce outside and works in according to his reads. Please understand that this is a very limited overview which does not approach covering even the basics as I see them. I’m not even going to touch footwork. There is a LOT of information out there on this stuff. I’m referring to inside and outside zone as wholly different entities, but they’re really not. It’s just simpler to explain this way.
First, an overview. Zone blocking is a concept that was kicked around the league for years. It finally came into its own in the 1990s with the Denver Broncos, under the guidance of Alex Gibbs. The essential concept (the “zone” bit) is that blockers are assigned to block zones as opposed to specific players. Offensive linemen who are “covered” (lined up directly across from) by a defensive lineman (not linebackers several yards away) are still doing much the same thing they would in a man blocking scheme: they hit the guy in front of them (though angled playside). The difference is the “uncovered” linemen, who step playside and help the covered linemen to that side until they have the defender controlled and one of them (typically the covered player, but not always) peels off to block at the next level. The linemen work to create a seal depending on how the defenders align themselves and react. The play side defensive linemen should be double-teamed at least initially, and the linebackers should be blocked by the covered linemen as the uncovered lineman overtakes the defensive lineman.
It’s easy to see where communication is a key to the success of this scheme as linemen need to first decide if they are covered (which can get a bit tricky depending on the defensive front), then communicate with each other to determine who will peel, which angles to take on the defender (e.g. do they push him inside or outside), etc. Much of this must be accomplished without verbal communication; linemen have to be able to read one another and the situation, and have to know how their teammates will react. All of this is done within the rules of the scheme, which exist to neutralize defensive tactics which create confusion, such as stunts, by dictating the actions of the linemen in order to reduce confusion; if they trust the scheme and execute as coached, it works. These rules are critical to the success of an Outside Zone scheme in particular (but also Inside schemes, don’t get me wrong), and the endless repetition and coaching required is one of the reasons it’s not as widespread as its effectiveness would lead you to expect.
Here is a quick video demonstration of basic techniques (double-team work starts at 1:10, watch the feet in particular. Not as much hand technique here.)
There are as many variations to the execution of a zone blocking scheme as there are teams that use it. The image most football fans have of “zone blocking” is the offensive line moving laterally while the back makes one cut and either bounces outside or cuts back. This is known as Outside zone blocking. The back reads the linemen (often using helmet placement as an indicator) to determine where the hole will be. The basic read progression starts at the end of the line; if the defender has outside position, the read is in and vice versa. Thus down the play side of the line, the positioning of the other linemen determines where the hole will be and the back makes his cut. This is the Alex Gibbs system used in Denver, Atlanta, Houston, and to some extent in Seattle. Each team implemented it somewhat differently and none used pure zone blocking (which I think always kind of pissed Gibbs off). There is a set of videos out there (the New Developments series) in which Gibbs teaches the fine points of the system to college coaches. It’s a wonderful series but very long and kind of dry.
Here’s a shorter video (8 minutes) in which he breaks down tape of Terrell Davis in Denver. It does a better job of explaining this than I do.
The less visually obvious but much more widely-used form of zone blocking is known as the “Inside” zone. It’s less visually obvious because it doesn’t involve as much clear lateral movement that gets the defense flowing to the sideline; the frontside and backside are less distinct when you run up the middle. Offensive linemen make the same reads to determine if they are covered, and uncovered linemen will still move to help their covered teammates. But this is still power blocking; the covered players are just trying to knock the guy in front of them back. The offensive linemen push the defense back, some peel off to block the linebackers, and the back picks a hole inside. It doesn’t involve as much lateral movement because the back is looking to run inside as opposed to outside of the OT, thus the name. This style of zone blocking is used throughout the NFL because zone reads help neutralize stunts and other defensive tactics that can cause havoc on man-blocking plays, but it requires less commitment that dedicated, pure zone blocking with outside and inside plays. Guys learn the concept of zones and the technique, and they’re good to go. It offers coaches some versatility with regards to their personnel as the guards and tackles are asked to do much the same thing on run plays, where on outside zone plays the tackles have a more difficult job due to the edge; some teams will only run outside zone to the strong (TE) side for this reason. This is the basis of the style that DJ Fluker learned in Alabama, and it was going to be a large part of what he ended up doing in the NFL regardless of which team he ended up with.
Many teams use or have used a combination of both of these systems as part of the chess match that is playcalling, but they can be and often are used exclusive of one another; most teams use Inside Zone blocking, but only a few commit to extensive use of Outside zone. That Fluker understands Inside zone, where the focus of the play is on the Guards, does not mean he is capable of the lateral movement of Ouside zone, where the Tackles are more important for setting up end runs or backside blocking. Based on my (admittedly limited) review of Alabama tape, Fluker has sufficient agility to peel and block linebackers at the second level, which he was often asked to do on inside runs, but lacks the quickness in his feet to perform the lateral steps of outside zone blocking at an exceptionally high level. If asked to do it, he probably can. But we won’t be looking at the late 90s Broncos reincarnated in San Diego.
I’m sorry if this isn’t as clear as it should be. There is so much information and variation among and between different systems that it’s really impossible to present a simplified view of the thing. It’s difficult for me to know if I’m providing too much or too little detail, so I’ll pay attention to the comments and try to explain or expand as people request.