Playbooks
Texas X-choice out of Shotgun Duo Twins Flex is a pass concept built around the Texas route (a running back angle route out of the backfield) paired with an X receiver choice route that reads the defender leverage at the top of the stem. This is a man beater at its core, since the choice route lets the X receiver break away from tight man coverage, while the Texas route from the backfield attacks linebackers who bite on run action or get lost in traffic. The primary read progression starts with the X choice route against man coverage, then works to the Texas angle route as the checkdown or hot read versus zone drops and blitz pressure.
Identify press man coverage on the X receiver pre-snap, since this is the biggest green light for the choice route to win immediately off the line. Watch the Mike linebacker at the snap, because if he steps up to fill the run gap or blitzes the A gap, the Texas angle route from the backfield will be uncontested in the flat or shallow middle. Look for a lurking safety or a user controlled defender sitting in the shallow zone, since this can jump both the Texas route and any underneath hot route adjustment if the quarterback stares it down too long. Cover 3 with a hard flat defender can take away the Texas angle route, so be ready to climb the choice route through zone coverage as your secondary answer. Cover 2 shells with safeties sitting deep can bracket the choice route at the top of its break, which pushes the read back down to the running back or checkdown option underneath.
Check the pre-snap alignment of the slot defender over the X receiver, since press man or tight bump coverage confirms the choice route will have room to break outside or inside based on leverage.
Use motion or a quick glance at the linebacker depth to determine if the Texas angle route from the backfield will be wide open, especially against Mike linebackers who show blitz or crash down on run fakes.
Hot route the second underneath receiver into a shallow drag if you diagnose zone coverage, since this gives you a built in zone beater without needing to change the whole play call.
Pair this play with HB Base or Inside Zone Split earlier in a series so the defense respects the run action, which sets up the Texas angle route to hit for extra yards after catch against aggressive box defenders.
Run this on second and medium to third and short situations where defenses are more likely to play man coverage or blitz, since both looks are exactly what this concept is designed to exploit.