Playbooks

Z Spot out of Shotgun Doubles Flex is a classic Spot Concept passing play built to attack zone coverage, especially Cover 3. The outside receiver runs a deep corner route while the slot man works a quick pivot into the spot area underneath, and the backside X streaks vertically up the sideline while the inside slot runs a short hitch. The running back releases into a shallow drag/spot route across the middle underneath. The primary read progression starts with the spot/pivot route in the flat area to hold the underneath defenders, then works to the corner route breaking to the sideline against the rotating safety, with the deep streak as the field-stretching outlet on the backside.
Pre-snap, check the cornerback depth on the outside receiver running the corner route, since a soft press or off-man alignment signals zone drop responsibilities that this concept exploits. Watch the free safety alignment before the snap, a single high safety rotating hard to the sideline is a Cover 3 tell that opens up the pivot route in the spot area. Post-snap, key the flat defender or curl-to-flat linebacker, if he sits on the pivot route without expanding, look immediately to the corner route sitting behind him. Beware of user-controlled lurk defenders sinking into the spot area, since a good user player can jump the pivot route and create a turnover if you stare it down too long. Man coverage with press corners and a blitz behind it is the biggest threat to this concept, since the deep routes take time to develop and the running back drag becomes your only quick answer.
Pre-snap, identify whether the defense is showing a single high safety or two high shell, since this concept thrives against Cover 3 and other zone shells with a hard flat defender.
If you see man coverage with no safety help over the corner route, be ready to hot route the corner into a fade or throw it early before the defender can undercut the sideline break.
Use the shallow drag from the running back as a built-in checkdown against blitzes, especially when facing a nano blitz or heavy pressure look, since it clears out fast and beats man coverage underneath.
Pair this play with RPO Peek Slant or RPO Zone Peek from the same set to keep the defense guessing between run and pass, then hit them with Z Spot once they start biting on run fits.
Best called on second and medium to third and long, since the layered route depths give you a high floor checkdown and a big play shot down the sideline in the same concept.