Iowa State: 3-High Safety Defensive Structure - Introduction, Aligning, and Coverage Calls

A handful of college programs over the last couple years have been  implementing a 3-high structure as an additional tool in the toolbox alongside zero, 1-high, and 2-high shells. Iowa state has been one of the early adopters, running a 3-high structure regularly alongside their 3-4 Hybrid Nickel. 

KEY POINTS

• Core Rules

• 3-down front.
• Mike/Will in the box typically. Sam coverdown often.

• Goals of the Structure

• Encourage run with a light box read. Stop run with aggressive middle safety (H) and overhang fits.
• Stop the RPO with overhangs.
• Prevent deep shots with pre-snap look. 3-Deep takes away MOFC/MOFO read pre-snap.
• Match gap creation across the formation with fits from deep safeties.
• Utilize multiplicity in 8th coverage man. Rotating coverages, blitzing into a 7-drop coverage, inverting coverages. 

• Alignments

• Safeties typically 8-10yds off the LOS.
• ILBs typically 2-3yds off heels of DL, over A or B gaps.
• Sam is pretty much always coverdown or apexed outside box.
• 0tech nose in most fronts.

• Run Fitting

• 3-down line are added on to by inside backers, with the playside backer becoming functionally a 3tech in the run. 
• Box players are spilling to the run-fitting safety.
• In run, the missing backer is replaced in the fit by the H (or BS, by formation). Safety fits to the playside edge generally. Misdirection can cause problems for these fits at times. 
• Against Y-Off, Sniffer, and FB sets, H and BS are able to match gap creation across the formation from depth.

• Pass Rushing

• Base rush is 3-down slanting to a side aiming to spill the QB out of the pocket in a single direction
• Mike will often add-on to the rush on a delay, shadowing QB to the spill side. 
• Other common call is to have DL rush central gaps looking to break the pocket inside-out, with Mike playing same role as above. 

• Multiplicity

• With a 3-down front and 3-high safeties, Iowa St. can call a drop-8 coverage on every snap. 
• This allows any of the 8 droppers to blitz, and maintain the integrity of a standard drop-7 coverage distribution.
• From 3-high, Iowa St. calls rotations and inversions of their coverages often. Corners, safeties, and overhangs will exchange assignments frequently. C1/C2/C3, Tampa, Quarters, and mixed calls are all on the table. 

ALIGNING and COVERING 

Depending on formation, Iowa State will play both split field coverage calls as well as full-field calls. 

3 RECEIVER SIDES

TRIO (3 split)

1. Cover 0. Man across the board, with BS/Sam sharing RPO rules. To the QB eyes hangs in coverage (Sam), and to the QB backside inserts to fit the run (BS).

2. Essentially a poach call, but the 3rd safety plays the role of poacher from an alignment to the strength, instead of from the backside in a 2-high shell. H takes the vertical of #3 while the #1 and #2 are covered with a 3-over-2 quarters call. 

3. Cover 1. H & SS man up to let backers play aggressively. Still trying to encourage short passes with depth of alignments. 

4. Tampa 2. Underneath defenders collision receivers before zone turning and gaining some depth. 

5. Cover 3 Boundary Rotation. H is hanging in the hole closing the seam, and driving down on ball thrown. Field CB is midpointing verticals of #1 and #2. 

6. Cover 2 H-man. One of the unique features of a 3-high is the ability to erase a man from the coverage, and still maintain drop-7 coverage distribution. H eliminates the #3 from the zone coverage, and Iowa State ends up with balanced 3-over-2 coverage to both sides. 

TREY (TE attached)

• Iowa State aligns 3-over-2 to the split-out WRs, with a safety and a backer stacked 1-2yds inside the #2. 
• Backer is either hanging to take away RPO, or folding into run fit. This depends on QB eyes to him/away from him, and backfield action. 
• The middle safety (H) is likely to be put man/man on the TE, fitting run on TE block. 

Rarely see Trey formations in the film I have access to. Both examples have QB eyes to the Sam. Sam is hanging and defending RPO before triggering to run play. 

2 RECEIVER SIDES

SLOT (2 split receivers)

• Iowa State makes a point to end the distribution with a 3-over-2. One of the main benefits of having 8 possible defenders in coverage is you can align/end the coverage with a numbers advantage look as long as you use the right RPO rules. 

1. Cover 2 Invert (Tamp2 Invert), mirrored. Safety pushes out to #1 right now, middle safety pushes to the seam/curl, mike drops to the hole, and CB bails fast to midpoint #1 and #2. 

2. Tampa 2. Mirrored. Starts as a drop-8 rush-3, with the mike spying the QB and blitzing on a delay.

3. Cover 3 Boundary Rotation. 

PRO/HBK (TE/HBK and split receiver)

• Safety and Corner play similar to how they play over a single-WR side (next section). The main difference is a backer or the H (middle safety) alignment depending on TE location. 

1. Corner run support (cloud). 3-over-2. Full-field call is C3 with the 3-high all dropping.  

2. Safety overhanging/run support (sky). Inversion of the previous technique. 

3. Against tight set "wing" looks, Iowa State aligns 4-high by bumping a cornerback to depth. Coverage is 4-man 4-under, with the unders playing run-first and the H/SS following TE/FB on gap-creation across the line from depth (pulls/kick-outs). 

SINGLE WR SIDE

• Pre-snap look always puts 2-over-1.
• Safety to the single side typically aligns 6-10yds deep, apexed between WR and EMOL. 
• Corner alignment is flexible, typically matching the technique and split rules in relation to the safety.
• When safety is 6yds deep, CB typically 5yds deep aligned inside eye. 
• When safety is 8-10yds deep, CB may align outside / press. 
• Nearly always playing aggressive to the run on single-sides.

1. Corner blitz. Safety will take #1 vertical or zone off unders.  

2. Safety blitz. Coverage call here is Cover 2 with the middle safety pushing over from the strongside to the backside deep-half, and the BCB collision #1 to the outside and sinking under the vertical. 

3. CLOUD call. CB is force and playing fast to the run. Can aggressively collision #1 while reading backfield action. Safety is taking all of #1. 

4. SKY (or invert) call. Safety is reading backfield action and triggering fast to the run. Corner takes all of #1. Must stay on top of all #1 routes. 

NUB SIDE (TE only)

• Depending on opposing team / expected run schemes, the edge/force player can be swapped between CB and Safety. 
• One player will align LOS, 1yd outside TE and fight any reach block and trying to keep outside arm free, maintaining the edge and forcing runner inside no matter what. 
• Second player will align 6-7yds deep, head-up on TE, fitting the last inside gap before the edge on run. 
• No film of pass plays from Nub sides / coverages.