Playbooks

X Seam out of Shotgun Open Flex sends the X receiver up the numbers on a deep seam route that bends toward the middle of the field, while the outside receiver on that side runs a corner route stemming from the seam release to clear space underneath. On the opposite side the single receiver runs a go route straight up the sideline to hold the deep defender, and the backfield player releases into the flat as a checkdown option off the blue route. The blocking is standard shotgun pass protection up front, and this is a man beater designed to attack seams in coverage or exploit a defender who overplays the corner, with the primary read starting on the seam route before working to the corner and checking down to the flat if both are covered.
Identify single high safety shells before the snap, this tells you the seam route has a clear throwing lane if the linebackers do not carry it vertically. Watch the middle linebacker depth at the snap, if he drops shallow to rob underneath routes the seam will beat him over the top for an explosive gain. Key the cornerback on the seam receiver, if he presses and opens his hips to run with the vertical stem, work the ball to the corner route or flat instead. Beware cover 2 shells with safeties sitting deep, since they can squeeze the seam route and force an incompletion or turnover if the quarterback stares it down. Look for a user-controlled linebacker spying the middle of the field, since a disciplined lurk defender can undercut the seam route if the quarterback telegraphs the throw.
Take a pre-snap look at the safety alignment before the snap, if you see two high safeties rotate late this seam route can split the gap between them for a big gain.
Use this play on second or third and medium when defenses are more likely to sit in man coverage or single high shells that leave the seam open.
Hot route the flat option to a quick out if you diagnose a blitz, this gives your quarterback a fast release valve against pressure.
Pair this play with Deep Outs or Dagger in your play-calling sequence, since all three attack similar vertical zones and force the defense to guess between seam shots and breaking routes.
Watch the corner route on the same side, if the defense rolls into cover 3 that route becomes your best answer since it settles in the void behind the flat defender and in front of the deep third corner.