Another HueJackson-favorite that shows up on tape several times against split-safety coverage (Cover 2, Cover 4, and Cover 6) is the ‘Split-Dig’ concept.
Split-Dig is a popular three-man concept that can be run out of a variety of formations including 2 X 2, or ‘Quad’s, if the running back is used as the #3 receiver.
The concept uses a seam route by the #2 receiver as a ‘clear out’, running off the deep safety to open up the dig and flat. Against split-safety coverages like the Tampa 2 and Cover 4, the dig-flat combination creates a vertical stretch, or hi-lo, on the flat defender.
Our example is run off play action against Cover 4, or ‘Quarters’ coverage (although this could be a Cover 2 with distorted zones due to the play action fake). In Cover 4 each deep defender (the two cornerbacks and two safeties) will cover a quarter of the deep field, with three underneath defenders.
Against Quarters the quarterback’s progression is ‘peak’ the seam at the top of his drop, then move to the dig/flat combination, reading the curl/flat defender for a hi-lo throw. If the defender gains depth in his drop to cushion the Dig, throw the Flat. If the defender jumps the Flat, throw the Dig.
Pay attention to the leverage by the left cornerback. Seattle plays an aggressive brand of pass defense in which the corners often press/bail, even in Cover 3 and Cover 4 in which they must protect a deep zone. Because the cornerback is playing outside leverage on Green (aligned outside the receiver’s outside foot) he is already at a disadvantage playing the dig route as it will break away from his position. The defensive back compounds this difficult assignment by getting caught moving forward at the snap, forcing him to reverse his momentum on the fly while peeking into the backfield before the ball is out.
The play action easily pulls the curl/flat defender to the line of scrimmage, creating a large throwing window for the Dig and leading to a 23-yard reception.