Levels

Pre snap, look at safety depth and width, if both safeties are aligned at 10 to 12 yards showing a clear two deep look, expect the dig route to threaten the void between the corner's cushion and the safety rotation. Watch the flow of the middle linebacker after the snap, if he sinks deep into a hook zone he can undercut the dig route and jump the throw, forcing the quarterback to work to the HB flat or the comeback route instead. Identify press man coverage on the outside receivers pre snap, since the natural pick from the stack release can be neutralized if the defense plays with inside leverage and squeezes the release point. Key the weak side linebacker or nickel defender assigned to the flat, if he sits and reads the quarterback's eyes rather than bailing with the hook route, he can jump the underneath route and blow up the checkdown option. A single high safety shell with aggressive man coverage on the outside receivers and a rushing four man front is the best defensive answer, since it removes the seam window the dig route relies on and pressures the quarterback before the levels combo develops.