Double left, jet left, quick 212, H-slant
U Shift Green, Left, West, F, Short, Spy, Two, Banana, Z, Over, Heads, Up, Four, 358, Smoke, Check, H, 2 Miami
Indeed, after the play is called -- laying out the snap count, shifts, motions, protection schemes, run and pass audibles, among other things -- the snap brings another myriad of variables into play: blitzes, protection and route adjustments and, on most occasions, onrushing defensive linemen with hate in their heart.
(Source: http://sports.espn.go.com/nfl/feature/featureVideo?page=qblearningcurve)