Playbooks
Quick Reference
Breakdown
Cover 3 Sky is a three deep, four under zone coverage out of the 3-4 Cub Base 5-2 personnel. The diagram shows three deep defenders running vertical zone drops to divide the field into thirds, while the underneath defenders (two hook/curl zone droppers and two flat defenders, including the Sky safety rotating down to the flat) fill the intermediate and short areas. This is a zone beater killer for offenses since it is a zone coverage itself, but on the defensive side it is designed to shut down quick game and shallow crossers by squeezing throwing lanes underneath the deep thirds. The primary read for the defense starts with the deep thirds, then works down to the flat and hook defenders to react to routes settling into the shallow and intermediate zones.
Defensive Reads
Check the safety alignment pre-snap, if both safeties are deep and one rotates down at the snap you are almost certainly seeing Cover 3 Sky or a similar single high shell. Watch for trips or bunch formations that overload one flat zone, since the Sky defender can get outnumbered underneath if the offense stacks receivers to one side. Post-snap, key the quarterback eyes and look for him staring down the deep middle third, that is the biggest exploitable seam against this coverage. This shell is vulnerable to deep out routes and corner routes that split the difference between the flat defender and the deep third defender, so user-control your deep third defender to close on comebacks. It holds up well against man beater combos like slants and drags since the underneath zone defenders can sit and read the quarterback instead of chasing receivers across the field.
Usage Tips
Call this on early downs or obvious passing situations where you expect a balanced or pass heavy playcall from the offense.
Use the pre-snap alignment of your deep thirds defenders to bait the quarterback into throwing outside the numbers where your corners have help.
Mix this in after showing Cover 4 Quarters or Cover 1 Hole from the same Cub 3-4 set so the quarterback cannot get a clean pre-snap coverage read based on safety depth.
Hot route your flat defenders wider if you see stick or flat concepts repeatedly attacking the Sky rotation, since the flat defender is the primary leverage point against quick outs and hitches.
Pair Cover 3 Sky with Olb Blitz on the following snap to punish quarterbacks who sit in the pocket expecting zone drops every down.
