The part of this that confuses me is we've been a zone scheme back to McCarthy. I don't see that part a significant change.
Not quite. Running primarily a west coast offense, McCarthy used a blended model that leaned more towards a power running scheme than zone blocking scheme. He also had bigger linemen that were suited for more of a power running scheme. As I mentioned earlier, Gute and LeFleur have been bringing in more agile linemen to run the ZBS.
In the power scheme, the play-side offensive linemen all have specific gaps to block. They are all told to down block, meaning to block the gap away from the play side of the run. Their first rule is to block a man in their back-side gap, or work to the second level if they have no defender in their gap. The running back has a bit more freedom in the power scheme. His initial instruction is to follow his lead blockers, the fullback and the pulling guard. But once he gets to the hole, he’s given more freedom to run to daylight.
In the zone scheme, the offensive line works tandem blocks to help the smaller offensive linemen deal with the bigger defensive linemen. On the play side of the run, the blockers kick out the edge defenders. The back-side blockers are taught to seal their blocks inside. When both the play-side and back-side blocks are executed properly, it creates one big cutback lane for the running back. In the zone scheme, the running back has specific reads he has to make, which determine precisely where he should aim to cut back to. The running back’s first job in the zone scheme is to identify the end man on the line of scrimmage (EMOLS). The back always has a specific aiming point. Every stretch play will start with the running back aiming to the tight end. The runner will read the EMOLS defender, and his position will tell the back if he should continue on his path to the edge or cut back inside. If the first read tells the back to cut inside, then the back moves on to his second read. His second read is the first defender between the EMOLS and the center on the play side of the run. The back again reads the defender’s position, which tells him to cut further back inside or go outside.
There are probably some good videos out there that illustrate the differences better than I can write it. The way the O-line executes its blocks are different and therefore can be a tough transition for guys that have mostly done it one way or the other. Some of those guys are smart enough to change, others not so much. A good GM/coach has to assess each lineman's ability and decide who fits the new scheme. I think the Packers staff has done that pretty well.
