pretty good...
that two yard rule must be before my time...
Ok, all shifts/motions/formation fouls are live ball fouls that occur at the snap, so at any point before the snap you can do "something" to get yourself out of a foul, in almost all occasions (kickoff 5 yard rule is the exception)
You know this, but trying not leaving anything out, at the snap, you have to have three men on the LOS, and everyone had to be set at some point for 1 second, altogether.
If you shift a lineman back and a back up, you don't necessarily have to do it at exactly the same time, but it is much clearer to everyone what is going on if that is the way that is done, and that is typically how it is executed. Yes, when the lineman on the end of the line is establishing himself as a back, he has to retreat, step back, whatever, to the backfield and come set for a second. Now he is a back, likewise, someone has to move up to replace him, now he is a lineman. He could go from the end of the line back to a RB with the QB, that is fine, as long as he gets set and establishes himself as a back.
Once he is established as a back, he can do anything a back can do, motion, whatever. The only thing he can't do is go in motion from the LOS and still be in that motion at the snap.
In crowded field, you see this all the time, several players may shift after initially being set in one location all at the same time, but they once they get to their new position, they get set for the one second and they are good to go. QB just has to pay attention to what is going on and not get in too big of a hurry... (see this a lot in jr high
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