Playbooks

Split Y Off is the 21 personnel wrinkle inside Shotgun that trades a third receiver for a second back, splitting your halfback and fullback (or second RB) on either side of the quarterback while the tight end aligns off the ball as a movable piece. Unlike Shotgun sets that stretch defenses horizontally with trips or bunch alignments, Split Y Off compresses the picture and forces the defense to declare its run fit before the snap. Two backs in the gun means the defense cannot cheat a safety down without exposing the seam, and it cannot stay in base personnel without giving up matchups on the angle routes and wheels that headline this set.
Read the box before the snap: if you count six or fewer defenders with a two-high shell, check into Inside Zone Split or Mtn Split Lead Zone and let the lead blocker clear the alley.
Against single-high man, go to Mtn H Angle or H Choice and let your back win in space, then hot route the split end on a slant or drag to clear the middle of the field.
On third and medium, Wheel Trail and PA Snag HB Wheel are your best answers versus Cover 3, but audible the tight end to a sit route if the defense shows two-high.
Use Read Option and Mtn Triple Option Lt sparingly to keep user defenders honest on your run keys, then come right back with Mtn PA HB Seam off the same shell.
Motion one back out wide before the snap to identify man or zone, then react: a defender following the motion means man, so run your angle and choice concepts.