"Gus, shouldn't we be studying for our Dynamics final?"
"Why yes, other Gus, we should be."
"Why are we writing this post, then?"
"Some things are more important than a good GPA and career opportunities, other Gus."
That's right, folks! I'm here with another installation from your favorite (ha ha I'm so funny) series of posts: Offensive Lessons. Today, we're going to be talking about the difference between zone and power blocking (I'll throw in a couple bonus vocabulary terms as we go along). A large effect of the Andy Reid acquisition was a switch from a zone run-blocking scheme to a power one. I remember that Jon Asamoah was referred to as a non-fit for the power scheme, and that this was used to justify letting him go in 2014 free agency. Some fans, however, may not know exactly what "power" or "zone" run-blocking means.
In a power run, every offensive blocker (this includes tight ends and fullbacks too, but I'll just refer to them as OL for now) will block a specific defensive player. Who blocks who varies on the alignment that the defense presents before the snap. The offensive center will make line calls--at my high school we used "Oscar" to indicate that an O-lineman was going on the the next level, and "Inky" to indicate that he was picking up a D-lineman (blocking in-line)--with the assistance of the quarterback, who looks for potential blitzers.
There are lots of different blocking techniques involved with power plays. Drive blocking is when an OL takes on a DL off the snap, getting under his pads and driving through him. Usually, a drive block will only be executed on a DL who is within two techniques (that's something I'll have to explain in my Defensive Lessons series) of the OL blocking. Drive blocking may sound straightforward, but it requires as much technique as it does brute strength.
Down blocking is a little similar to drive blocking. Off the snap, the OL steps to place himself between the hole where the ball is heading while simultaneously engaging the defender with his hands. The OL then (a really good OL will do this all at once) push the defender away from the direction in which the ball carrier is running. Unlike drive blocks, down blocks can effectively be performed on a defender playing away from the line of scrimmage, like a linebacker or in-the-box safety.
Reach blocking is usually performed on the outside of the offensive line, by tight ends or tackles on defensive ends and linebackers. In a reach block, the OL fires out of his stance with a quick step outwards and engages the outside shoulder of the defender with his own outside hand. He then punches his inside hand to the defender's chest, moving his feet to position himself to push the defender away from the play. Reach blocking is also referred to as hook blocking or J-blocking.
Influence blocking is a variation of down blocking. In an influence block, the OL will make a step as if he is down blocking his defender. When the defender attempts to cross the OL and head to where (he thinks) the ball carrier is headed, the OL then engages his hands into the defender's chest, works his feet around to the opposite side of the defender, and seal him out of the play. Influence blocks are very useful on runs where the tailback is going to jab-step outside and then cut back in--for instance, a guard might influence block a defensive tackle if the tackle moves to the outside where the ball carrier initially aims, thus allowing the DT to move unwittingly moving himself out of the play and then preventing him from pursuing the ball carrier when he cuts back in.
Pull blocks are usually performed by guards and sometimes tackles. In a pull block, the guard will avoid engaging the defender over him off the snap. Instead, he will throw his pull-side elbow back , opening his body toward his pull direction, and huff-and-puff his way to the defender who he is going to pull block. In addition to traps and sweeps, pull blocks are used to bring an offensive lineman around and hit a linebacker on the second level. Usually this is accomplished with a pin-and-pull or "pencil" combination block. In pencil blocks, the center or pull-side tackle is going to down block the defensive lineman (if any) who is aligned over the guard, "pinning" him in place while the guard moves on to his assigned defender.
Double team blocks are a cool combination of down blocking, pull blocks, and sometimes reach blocking. In many cases, when a defender is lined up between two OL (usually over one of their shoulders), the two OL will simultaneously engage him off of the snap. They will move the defender in the appropriate direction, after which one of the OL usually scrapes off and moves to another defender. This allows the OL to move a really big and/or dominant player out of the way and then pick up another guy for the ball carrier.
"That's all really interesting, Gus, but can you show me a play that is a good example of power blocking? A picture is worth a thousand words, you know."
I'm glad you asked! Of course I can (and will) spend my time to draw up a power run play for y'all to look at.
Disclaimer: These plays were drawn using a slick combination of MS Paint and a pencil, each of which necessitates using my shaky hands. Therefore, they won't be winning any art contests.
The play above is 36-Trap out of Pro Right Down (a weak-offset I formation for those of you who like hearing it that way), being run against a 4-3 Odd defensive front like the Broncos used to run. Let me break it down from right to left on the line.
Tight end: releases and reach blocks the strong-side linebacker.
Right tackle: down-blocks the 3-technique defensive tackle.
Right guard: releases and reach blocks the middle linebacker.
Center: down- or reach-blocks the 1-technique nose tackle.
Left guard: pulls and blocks the strong-side defensive end.
Left tackle: down-blocks the weak-side defensive end.
Fullback: goes through the line and picks up the weak-side linebacker.
Wide receivers: depends on defensive alignment.
The tailback will take the hand-off and then read the guard's pull block on the playside end. If the end crashes inward, the guard will engage and try to turn the end inward with a reach block (seal him), allowing the tailback to bounce outside. If the end bides his time outside, the guard will drive block him even further out of the play. In this case, the tailback will just go straight through the 6-hole (between tackle and tight end).
As you can see, in a power run play the ball carrier just reads one block--the pulling guard's. This holds true for most power run plays, with very few exceptions (a historical one being the Packer sweep, in which the tailback may read up to three different individual blocks). Power blocks, it might be said, are used on zero- or one-read run plays. Since the ball carrier on a power play only needs to read one defender (and thus one hole), power running backs can sacrifice change-of-direction agility for explosiveness and strength. LeGarrette Blount and Adrian Peterson, for example, are prototypical power running backs in today's NFL.
In zone blocking, each OL does not have his own man to block. Instead, the line as a whole works together to move defenders out of the way. Each OL has a specific zone, which usually extends to three techniques away from his heads-up technique. For example, a center in a zone play might engage a defensive lineman anywhere from a 0-technique (right over his nose) to a play-side 2-tech (heads-up on the play-side guard).
In a zone play, each man on the line will check his own play-side shoulder and the nose of the next OL to the play-side. If there isn't a defender lined up over one of those (or somewhere between the two), he will next look for one directly over him. At the snap, the OL will move together and pick up defenders in this pattern, first engaging the defenders who are lined up on the line of scrimmage and then (for those OL who were not covered) moving on to the next level of defenders. When you see a zone play, it usually looks like a bunch of double teams or down blocks, except that the ball carrier is actually running toward the direction where the blockers are pushing defenders.
The main reason that zone plays block toward the running back's initial direction is because they want the running back to read and react to any holes that open up for him to squirt through. A zone play will usually be run to an outside hole, allowing the running back to either keep running and turn the corner up-field or to cut back and head in the opposite direction. Ball carriers on zone plays have to have good vision and change-of-direction ability. Most running plays out of shotgun formations will be zone, which allows the ball carrier to use the extra room to read and then accelerate through the hole he picks. Almost all zone plays are run out of single-back formations, since the tailback needs that room to dance around a little before hitting his hole.
Here's a picture of a zone running play:
This is 26-Zone out of Pro Two Right (pro quads, singleback slot, whatever you want to call it) from under center. As you can see, even though the ball is headed to the same hole as in 36-Trap from above, the blocking is very different.
Tight end: engages the strong-side defensive end, waits for the tackle to take over, then releases and picks up the strong-side linebacker.
Right tackle: double-teams the strong-side defensive end with the tight end.
Right guard: engages the 3-technique DT over him and moves him to the play side.
Center: since not covered to the play side, goes to the middle linebacker.
Left guard: engages the 1-tech NT and moves him to the play side.
Left tackle: seals off the weak-side defensive end.
Wide receivers: depends on defensive alignment.
The tailback will take the hand-off, and will read the line of scrimmage. If the defensive end can't get around to the outside of the combo block on him, the tailback can just speed up and go around the outside of the formation into the open field. If the defensive end fights outside and controls the edge, the tailback will next look inside for a hole, hitting the one that opens first.
As you might think, zone plays require a back who can really react to how defenders are moving, change direction quickly, and accelerate explosively. Jamaal Charles and LeSean McCoy, for example, are great zone running backs. Since they require backs to scan multiple holes in the line, zone runs can be thought of as multi-read plays.
As laid out above, power and zone run plays have very different objectives. Power plays require ball carriers to hit their holes quickly and decisively, and rely on sheer speed, strength, and size from the runner as well as strength and length from the blockers. Zone plays are best for ball carriers who have great vision and quickness to compensate for a low amount of tackle-breaking momentum; in zone plays the blockers have to be strong enough stay between the defender and the ball carrier for him to read and choose a hole to squirt through (although good zone blockers are also more athletic in order to more effectively chip and release to the next level).
I hope that this has been enjoyable and informative. Go Chiefs!