crackback
Reverse direction hit
A crackback is a football block in which an offensive player, typically a wide receiver, moves back toward the ball and hits a defender from the side or behind.
The block is legal in some situations but often penalized when targeting a defender's knees or executed blindside: He was flagged for an illegal crackback block.
The term also appears in lacrosse for similar hits.
blindside
Surprise with unexpected force
linebacker · tackle · hit · snap · formation · downfield · gridiron · scrimmage · offensive · lineman