Quick Question about defense positioning?

[PatsOwl]

I was just hoping someone with more X and O's knowledge could help me.
I was wondering, when the defense have their play called, is it even specific to where they stand on the field? For instance, when watching CB's they often stand close to the WR at the line, then drop back, then forward etc.
Is this called to them at the play, such as this play you will be 5yds behind the line. Or is it almost like an audible that the CB's call themselves? Do they see the offense and think... 'hmm quick slant, ill move up to the line' etc.
I guess it similarly applies to LB's, when they blitz/drop in coverage. Is it the defensive play that states they are in zone but fake the blitz? Or do the players simply determine that themselves?
I hope this post made sense. Its just always bugged me as i wondered how much freedom the players get.
Cheers

 

[FreeTedWilliams]

The defense will call formation 3-4 or 4-3 and then the type of coverage (man to man, or zone or a combination of both), But defenses have audibles just like the offense, if you have the original 3GTG, thier is a great part in SB XXVI where Lawyer Milloy is going over all the hand signals for the coverage adjustments with his other DBs. SO the short answer is yes, the defense will adjust thier plays at the line, but they alos have to communicate it to each other, when someone is wide open, usally it means that one guy in the defense is playing zone, and the other guy is playing man to man, and that is where the big play happens.

The DBs move around before the snap because they must hide their called coverage from the QB, it is a game of cat and mouse. If you watch the replay of the INdy game, the Pats D always is looking over to the sidelines like they are confused on what the call is. I've heard Peyton talk about this before, and he has figured out, that they are actually faking it, and that once the ball is snapped they fly exactly where they are supposed to be.

SO no, a defenseive guy can not just change the play on his own, without letting the other ten guys know what he is doing, especially in the Patriots "gap style" defense. the slots between each offensive lineman is assigned a number or letter, For instance the slot between the Cneter and the Right Guard is usually called the 2 hole, or the A gap in the Pats system. For every defensive call, the Pats guys know who is responcible for stopping a run into each and every gap. Most of the time, Wilfork is responcible for the A and B gaps, and so forth

 

[BHSL2]

Also, players in coverage will shade their man so that it puts them in the beneficial position to counter the offenses' formation. If you're lined up against a receiver in the slot, as a d-back, you give the receiver a bit more "cushion", or space in between you and him to negate the big play. Or, you can line up closer to jam him and offset the timing of the play if you feel it will be a quick slant. It depends on what the defense feels they should do.