The drive route (red) is designed to remain shallow throughout the play while a 10-12 yard dig route (yellow) forms behind it by the in-line tight end. The weak-side receiver ("X" or split end) generally occupies the cornerback to make space for the drive route which will reach a depth of 4-6 yards by the time it reaches the far numbers.
Flanker drive puts stress on the middle linebacker (M) as he needs to choose whether to drop to cover the tight end or to collapse onto the drive route. With good rapport between QB and receiver, the drive and dig routes will sit in between zones and get up-field immediately upon catching the ball. On the weak side, the X and W will occupy the corner, nickelback and free safety.
Against man coverage, the drive route will run away from the corner assigned to him. With the corner on his back, the Z receiver can catch the ball in full stride.
The QB's reads will depend on the perceived coverage, but the reads are often drive, to dig, to check-down (running back swing). Variants of this play can place the drive route on the opposite side of the tight end drag (Hi-Lo Opposite) or use double drive routes from opposite sides of the field (Mesh) that creates a natural pick.
Outside References
1) St. Louis Rams Shallow Cross Concept
2) Georgia Bulldogs Passing Concept (Shallow, Y-Corner)
3) Play Diagram - Flanker drive explained
4) The shallow cross, drag, and drive in the west coast and spread offenses
5) West Coast Offense Playbook: Brown Right F Short 2 Jet Flanker Drive
6) Classic WCO play - Flanker drive
7) Lions vs Packers All-22 Drive Concept
8) The Pass Concept that Changed My Life
9) West Coast Offense.pdf
