The "Collision" is where the play begins. For a cornerback aligned in press-man coverage, the first two yards off the line of scrimmage (LOS) belong to you. The goal of the collision is simple:
However, statistics show that off-coverage gives up a 78% completion percentage due to pitch-and-catch plays. Press coverage, when executed with proper fighting and reading, drops that completion percentage to 52%. Collision Cb Fighting Read