Any horizontal stretch play can be run from any formation and any depth of drop. The quarterback will typically key on one area of the defense; in a horizontal stretch, this is typically done in quarters. The play is usually designed to attack either the deep half or shallow half of the field. Pre-snap, the QB will attempt to diagnose the defensive coverage and predict what side of the field will be more effective for the play. A horizontal stretch play can be read either outside-in or inside-out; it will depend on the play call, as well as what the QB reads in the defense. If he doesn’t find an open receiver he will either throw it away or check down to the RB. Look at this example of a 4 verticals play:
In this play, the defense is in a cover 3, meaning there are 3 players assinged to cover the deep sections of the field. The Giants have 4 receivers running deep routes
meaning one will be left uncovered, shown here in green:
Here is the play in slow motion:
In a stretch concept, the WRs goal is not to get separation, but to find the holes and seams within the zone. Beating one defender is less important when there is another defender ready to take over. With this in mind it is important for the receiver to be able to identify the coverage as well. For example, in a cover 2, the middle deep area of the field is usually vulnerable. In a cover 3 or 4, the flats and shallow sideline areas are vulnerable. Once they find a hole in the zone, a receiver will generally stay in the hole and not move far or fast from it. In this play,
The receiver to the near side runs a short in route, while the RB runs a swing route, shown in green. To the opposite side the receivers both run out routes.
The defense is in a cover 4, meaning both safeties and both cornerbacks have responsibility for the deep sections of the field. The OLBs have responsibility for the flats, shown here:
When the play starts, the CB drops into his deep zone, and the OLB must decide to cover either the in route or the swing route, shown here:
The green zones are the possible open areas, depending on the OLB’s (in blue) decision. The OLB moves out to cover the flat, leaving the middle of the field open for the in route shown here:
Watch the play in slow motion,
Notice how the receiver slows and takes shuffle steps once he passes the defender into the open space.
The running back has to read the defensive front and identify any blitzes. The RB is usually responsible for supplementing the pass blocking initially. The goal is usually to have one more blocker than pass rushers. If the RB identifies a 5 man rush, he will stay in and block. If he identifies 4 or less, he will release into the field as an outlet for the QB.