SHADOW BLITZING is the art of blitzing an LB, or somebody in a zone, and user controlling him to get the blitz. the only catch is that you have to line up BEHIND a D-lineman to get this effect.
WHAT THIS DOES: yes, some people will be mad, but this takes advantage of the AI. it makes the Lineman's AI think that he's guarding the other guy as well, and the other guy gets right through. I like to contain on the other side as well.
I normally do it out of 46 Normal. you can try other formations, but I'd stick to 46 normal because of how every1 is set up.
Subject: Shadow Blitzing Scheme 
