This will be part of an ongoing series on the merits of implementing a zone read scheme into the Titans offense.  The purpose is to identify the interests, problems, and risks involved with installing this offense in the NFL.

In Part One of this series, we went over why I believe this offense is worthy of installing as our offensive scheme.  The intent of this post is to examine the fundamental principals, evolution, and some new wrinkles to the zone read offense.

The Zone Read

Rich Rodriguez is generally given credit as the inventor of the zone read offense.  What better way to begin than by hearing the basics of the offense from the man himself.

RichRod does a pretty good job of summing it up.  There are various different looks, but the premise remains the same.  The quarterback's job in this play is to read the backside end (or in some cases the backside DT as we'll see later).  Chris over at Smartfootball.com has an excellent diagram that shows the basic premise:

via smartfootball.com

If the end collapses, the quarterback keeps the ball.  Conversely, if the end heads up field, the quarterback hands the ball off.  This decision is made in a split second at the "mesh point" where the running back and the meet in the backfield.  What's unique about this play is that for scheme purposes, the quarterback is treated as a blocker because he eliminates the weakside end from the play.  In this example above, consider that if it was a basic single back run, the defensive men in the box would out number the offensive linemen 6 to 5.  However, if the weakside linebacker comes upfield to stop the field, it's suddenly 5 on 5.

From there, the play then becomes a basic zone running play, which our offense is familiar with.  It's the foundation on which Denver built it's running game around in the late 90's, where Dinger cut his teeth as an NFL positional coach.

Zone Blocking

Most credit the creation of the zone running play to Alex Gibbs.  He's bounced around, but is most well known for being the offensive line coach of the Denver Broncos under Mike Shanahan.  This slideshow does an excellent job of giving a rundown of the fundamental concepts involved with a zone running play.  I'd encourage everyone to read that before continuing any further.  It's worth noting that there are all sorts of variations on these principles, and many books have been written on the subject.  I don't pretend to be any kind of an expert, but would like to lay out some of the most basic ideas.

The premise is the same whether it's an inside zone run or and outside zone run, just with slightly different assignments.  In general, the idea is what you'd expect.  The line is going to block an area and the way the opposing team defends will determine the way you block that area.

For this example, let's use the inside zone run.  When the offensive line gets to the LOS, they are going to make some pre-snap assignments based on the alignment of the defense.  Where the opposing team puts their down linemen will dictate how the offensive line will block.  If you're covered (a lineman is directly in front of you), you're generally going to look for help from the lineman to your weakside.  Let's use the diagram below (not out of the shotgun formation, but it will serve our purpose):

via upload.wikimedia.org

Consider that in our zone read scheme, the fullback will likely be substituted for a wide out in the slot to the right or left.  The QB will be in the gun with the running back to his left.  In this example, the TE would block the strongside defensive end with help from the RT.  Their responsibility is to seal that DE off to the right.  The RG and C seal the strongside DT off to the left.  The weakside guard and weakside tackle will block the weakside DT.  The defensive end is "blocked" by the quarterback as he is forced to deal with his running threat.  Also, in a double team the "helping" lineman will engage in a double team block, and then release and head up field to the linebackers.

Before we get to the next part, a quick refresher on running gaps.  The "A" gap is the area between the Center and Guard.  The "B" gap is the area between the Guard and Tackle.  And, the "C" gap is the area between the Tackle and Tight end.

Once we've reached this point, it's in CJ's hands.  He's responsible for reading the defensive linemen and responding accordingly.  CJ's going to be reading the DT on the strongside.  If there is room, the running back is going to always attack the B gap.  However, if the DT cuts outside (away from the center), it's going to close that B gap.  It's the running back's responsibility to read that, plant, and cut to the inside.

As you can imagine, it can get a lot more complicated than this.  Denver basically built an entire offense around the concepts.  But, the premise is simple.  The offensive line blocks an area, and the running back reacts to the gaps in the coverage.

The evolution of the zone read and new wrinkles to the offense

Inside zone read of the DT.  As one of our readers, NewsToTom, pointed out, the read the quarterback makes doesn't necessarily have to be the defensive end.  Trojan Football Analysis does an excellent job of describing the inside zone read of the three technique DT.  The three technique means that the DT is lined up on the outside shoulder of the RG.  In this play, the weakside tackle is going to be responsible for blocking the defensive end to the outside of the play.  At this point, the quarterback may have an isolated matchup with a DT.  If the quarterback finds the DT out of position, he keeps it.

The play has its advantages and disadvantages.  One one hand, I'll take Vince one on one against any DT in the league in the open field.  That's foreign territory to a tackle, and one that Vince can win 7/10 times.  However, I'd be extremely hesitant to send Vince into the teeth of a defense on a regular basis.  I think this is an interesting play to throw in one or two times a game because it exploits the conventional responsibilities of the defensive tackle and defensive ends.

A video of the play is below:

The Speed Option

This is a fairly simple play.  The quarterback is going to sprint off tackle to the running back's side of the play.  The back trails as the pitch man.  Generally, the quarterback is either going to be reading the defensive end or the outside backer to determine whether to keep or pitch the ball.

The University of Charleston has found another way to employ the speed option (see below).  They the slot receiver in motion behind the quarterback.  The ball is snapped, and the running back is now the lead blocker with the QB running the speed option and the slot receiver as the pitch man.  -cough- Dexter McCluster -cough-

Another similar way to run this would be by beginning with a typical zone read out of a two back set on both sides of the quarterback.  If the quarterback elects to keep the ball, the second back comes around his backside and they now execute an option play to the outside.  You can see an example of this play at about the 1:05 mark of the first video in this pos with an explanation by Coach Rodriguez.

Zone-Read Bubble Screen

Again, Chris over at Smartfootball.com has a great article on this subject of new variations to the zone read that I would encourage everyone to check out. 

One of which is the addition of the bubble screen.  In this play, the quarterback can either hand the ball off, keep the ball and run, or keep the ball and pass it to the WR in the flat.  You can see an example of this in the video below.

This just scratches the surface of the creative things with this offense.  I believe that it is the offensive coordinators responsibility to put his players in the position that maximizes their potential.  This offense provides that opportunity.  The hardest part is committing to running out of the shotgun as the primary set.  Once you've done that, the transition should be smooth as a form of zone blocking is already in place, and the two most important playmakers ran this offense in college.