Levels is one of the very best pass plays to attack the Cover 2 pass defense. Smash (Hitch by the #1 outside WR and Corner by #2) is most people's weapon of choice vs. Cover 2, but Levels has a shorter and easier throw than Smash and the Dig route to the field has better leverage on the hash safety than a Corner route does. Safety Leverage is one of the most underrated aspects of the passing game IMO. Also, on Levels your QB is reading the OLB vs. Smash where he is reading the CB, who is generally the defense's quickest and best pass defender. Smash can be dangerous vs. a CB who is good enough to play both the Hitch and the Corner route.
