Playbooks
Curl Combo out of Shotgun Empty Trey Flex spreads five eligible receivers wide with no backfield help, stacking curl routes at varying depths on the trey side while the backside receiver runs a complementary curl or hitch to hold the corner. This is a zone beater designed to attack the soft spots between underneath zone defenders, using the curl depth to settle in the honey hole against Cover 3 and Cover 4 shells. Since there is no running back, protection relies on the offensive line in five man protection, so the primary read progression starts with the trey side curls working outside in before checking the backside curl as a hot route valve against pressure.
Pre-snap, identify whether the defense shows two deep safeties or one deep safety, since Curl Combo is most effective against single high shells like Cover 3 where the curls sit in the soft spot behind the underneath linebackers. Watch the flow of the middle linebacker after the snap, because if he sinks deep into the curl zone he can undercut the primary route and force you to work the backside option. Against Cover 2 or Cover 4 shells with two deep safeties, the corners often sit in hard outside zone leverage, which can jump the shorter curl routes if you telegraph the throw, so hold the ball an extra beat to let the route mature. Be alert for user controlled defenders lurking in the shallow zone or dropping into the curl window late, since a savvy human defender will bait the quarterback and jump the route for a pick. Man coverage with press corners at the line signals trouble for the curl concept, since the stop and turn nature of the route is vulnerable to a jam, so consider hot routing to a slant or out if you see man alignment pre-snap.
Check the safety alignment before the snap to identify two high versus one high shells, since Curl Combo thrives against single high looks where the curls settle in soft zone windows underneath the deep third defenders.
Use the trey side stack to influence linebackers and open passing lanes, working your first read to the shortest curl if the underneath defender bites on the deeper route.
Because there is no running back protection help, hot route the backside receiver into a quick out or slant against known blitz teams to give yourself a fast throwing option versus five and six man pressure.
Pair this play with WR Screen or QB Draw earlier in a series to bait linebackers into crashing downhill, then come back to Curl Combo to exploit the vacated underneath zones.
This play is best called on second and medium or third and short to medium distances where the curl depth naturally matches the sticks and gives you a high percentage completion against zone heavy defenses.