Originally Posted by The Pencil Neck
CBs shade their coverage based on where they have help and IF they have help.
If a CB is getting safety help over the top, that means that he has to take away the underneath. If a CB is getting safety help on the inside, that means he has to take away the outside. If a CB is playing straight up man, he's got to be on the guy like glue.
Plays are designed to pull that safety in lots of different directions. But once the ball is in the air, the safety has to be able to respond and take care of his responsibilities.
In the play we're talking about, KJ had safety help to the inside and he played it that way. It wasn't his job to take away the inside.
That is called double coverage. If a safety is playing in a deep zone he's looking at more than one route. There is no such thing as inside help unless the safety is doubling up on your man.
If a safety is in a medium zone then he's playing the zone and not your man. He's there to provide support, not have you pass your man off to him because if the receiver runs past the "inside help" then he's going to be open anyways.
If the safeties job is to follow the receiver even after he crosses his area then he's playing man.
If he's just in a zone then Jackson will be beat after the receiver crosses. You don't rely on your help. You use it but you are not excused if it fails you.