Playbooks

Mtn Spot out of Singleback Wing Pair 13 personnel is a classic Spot concept pass play built to attack zone coverage, particularly Cover 3. The backside receiver runs a deep corner route while the two receivers to the strong side stack a corner and flat combo, with the inline tight end running a quick drag/spot route underneath to settle in the void, and the wing back releases out to the flat as an extra checkdown option. Protection is a straight five man slide with no play-action fake, so the primary read progression starts with the underneath spot/drag against the flat defender, then works to the deep corner routes on either side if a zone defender opens a passing window.
Presnap, check the safety alignment, if you see two high safeties rotating to a single deep defender post snap that signals Cover 3 and this play should hit its corner routes or the spot underneath. Watch the flat defender or overhang linebacker at the snap, if he sinks with the corner route the drag/spot route sits wide open in the void behind the underneath zone. Man coverage with press corners at the line is the biggest counter to this concept, since both corner routes rely on grabbing separation off zone defender leverage rather than beating a man defender one on one. Look for user controlled defenders lurking in the shallow zone, since a smart user will jump the spot/drag route, if you see that happening reset your eyes to the deep corner route away from the user. Blitz packages that bring five or six rushers can beat the slide protection quickly, so identify the Mike linebacker presnap and check to a quicker hot route or throw the spot route immediately if you see extra rushers on the strong side.
Use this play on early downs or third and short since the spot route underneath gives you a quick, high percentage completion against zone drops.
Presnap, identify if the defense is showing Cover 3 or Cover 4 shell, since the two corner routes stretching the sideline are designed to sit in the honey hole against three deep zone defenders.
If you see man coverage presnap, consider hot routing the spot route to a quick out or checking to Y Stick instead, since Mtn Spot is primarily a zone beater and loses some effectiveness against tight man coverage.
Pair this play with Mtn HB Plunge or 26 Duo earlier in a series to get defenders keying run, then hit them with the corner routes off the same Wing Pair look once they start creeping linebackers into the box.
Against Cover 3 Sky or Cover 3 Cloud, throw off the flat defender's drop, if he sinks with the corner route the drag underneath is wide open for an easy pickup.