Ed. Note: This was passed on to me by Bill Mountjoy, and some of the images are from Ron Jenkins.
There are many qualities that a quarterback must possess. However, the most obvious is the QB’s ability to throw the football. Throwing the football requires a tremendous amount of coordination and teamwork for proper execution. The QB can make up for some deficiencies with proper reads. Whether it is the Pre-Snap Read, Reading on the Move, or Adjustments in routes, the QB’s recognition, anticipation and reaction are based upon his knowledge of the offense as it relates to what he sees.
Pre-snap read
The QB must make a “Pre-Snap Read” confirming the defensive secondary’s alignment. The PSR provides the QB with help in making the proper throwing decision; i.e., allows the QB to establish his thought process prior to the snap. There will be many times when the QB can determine what the coverage is before the snap. About eighty percent (80%) of the time the coverage will be given away by someone’s alignment in the secondary, typically the second defender inside. Even when the total coverage is not given away, through observation of particular alignments, you will be able to eliminate some coverages or narrow to a “Hard Focus” area. The QB must approach the LOS the same way every play and get his hands under the center. The PSR process includes a “Soft Gaze” left, middle and right. The purpose is to identify (1) the depth of the corners, (2) number of safeties, (3) weakside flat defender, and (4) the number of run defenders (“front”):
- Find the Free Safety (“FS”) and Strong Safety (“SS”) to determine the type of front – seven-man or eight-man. If the safeties adjust to motion, be aware of a possible blitz.
- Find the weakside linebacker (Whip (“W”)). This is a crucial read to recognize an outside blitz. It is the QB’s responsibility to adjust the protection to handle the outside blitz or allow the receivers to read “HOT.”
The PSR is only the first step in the throwing decision. The QB must identify the primary defender (the “Key”) to read (“Hard Focus”) and determine where to throw the ball. The Key is determined by the pattern and the related PSR. The ball is thrown based upon what the Key does within the QB’s line of sight. For example, on a strong side route the PSR must identify the SS. Upon the snap the strong safety can either man-up, cover the flat, cover deep third (1/3) or cover deep quarter (¼), and it is the SS’s action that allows the QB to decide where to throw the ball. Depending upon the route, the SS’s action might change the key (Reading on the Move [“ROM”]) to the Corner (“C”) or FS. The QB will make their throwing decision based upon what happens in his Hard Focus area and the related routes within the “line of sight”; i.e., does the Key rotate, invert or play man. When the QB keys defenders, not receivers, there are fewer throws into coverage.
- Basic Coverages
A brief summary of coverages, including strengths, weakness, and how to attack them follows. The summaries include a place (“Patterns”) for the coach and QB to write in their specific routes to attack the coverages. These are the basic coverages: Invert (“sky”); Rotate (“cloud”); Two Deep, Man Under Two; Man with a Free; Man – Zero; Quarter, Quarter, Half; Zone Blitz; Robber; and Prevent.
Three Deep – Invert (“Sky”)

The PSR is based on the alignment of SS and C on the strong side. Teams will typically define the TE as the strong side, however a scouting report will provide this information. If the SS is aligned with less depth than the C, the read is an invert by the SS; i.e., the SS is covering the flat, if a receiver is in the flat. Confirm 3D coverage by the alignment of the FS. If the FS is off the hash and favoring the middle, assume that it will be a 3D. Also the QB must be aware of the weak side, if the Weakside Linebacker (“W”) is in a stack (lined-up behind a defensive lineman or end) or walk (off the LOS outside the end) position, it denotes a soft corner, with W responsible for the weak flat. If the end (“E”) is up on the LOS or in a three (3) point stance, assume he will rush. If you are throwing to the strong side upon the snap you can determine whether E is coming or has curl or flat.
- Strengths
- Safe – always three deep
- strong side force against the run
- SS can get under an out and may be able to get under a stop or flat depending upon the wide receiver splits
- can cover eight zones with a three man rush
- can still bring four with strong side contain and have seven in coverage
- Weaknesses
- Versus eight in coverage the defense can only rush three with five or more to block them
- four defenders underneath to cover the six zones – large curl and horizontal seams
- no leverage on wide receivers; i.e., cannot bump or push inside
- possibly late to cover stop and flat, both weak and strong
- cannot cover a strong side flood route (three or four receivers in the pattern) without E, then it is a three man rush
- weak flat
- weakside force
- How to attack it:
- Stretch vertically and horizontally
- plenty of pass protection
- throw in the alley created by sending three on two in the perimeter (“flood type” routes)
- weakside curl & flat
- sprint away from SS
Three Deep – Rotate (“Cloud”)
The goal of this coverage is to take away the short passing game or protect against the wide side of the field when the offensive formation is strong into the boundary (short side). The PSR is based on the alignment of the SS and the C. The SS must be deeper than normal in order to cover the deep middle or deep outside (is aligned deeper than the adjacent C), the read is a rotate by SS; i.e., SS is covering the deep middle or outside. Also, in this coverage the C to the side of the rotation will be tight (up close) on the wide receiver as they have the flat. The secondary can disguise this by having both Cs up and on the snap the away (from the rotation) C back peddles to deep third [1/3] quickly (“bails”). However, we can determine the side of the rotation by the position of the Outside Linebacker (“OLB”). The OLB, whether W or S away from the rotation must be stacked or walked off as they have flat away from the rotation. You can confirm the 3D by the alignment of the FS. If the FS is off the hash and favoring the middle, assume 3D.
- Strengths
- Safe – always three deep
- force (to the rotation) against the run
- leverage by the C (shut down weak flat or out)
- can cover eight zones with a three man rush
- can still bring four with force and contain to the rotation, and have seven (7) in coverage
- easy to disguise (more…)