What is a "Split Rule" when it comes to WR?

[NovaScotiaPatsFan]

Hey all, as most of you who read my posts know I'm not the most knowledgeable football fan, but I'm always trying to increase my knowledge. Normally I can just teach myself, but every now and then I need some help.

I downloaded some old Patriots playbooks and have been studying some plays, trying to figure out how and why the Pats line up the way they do, learning about play and formation names, etc.

One thing has me stumped though, and that is the "Split Rule"

As you can see here if the Z receiver is supposed to line up in his normal formation it's referred to as "Split Rule" I'm just wondering if any football coaches or old fans among us know what this is and could explain it to me, unfortunately the Google results were kind of confusing and most of them about defense rather than offense.

Thanks for your time,
NSPF.

 

[Brono]

Some example split rules:

X lines up at a point that splits the difference between the tackle and sideline.
Y lines up at point that splits the difference between the Z and the tackle.
Z lines up 3 yards outside the hash mark.

So based on your diagram above, I would interpret Z-normal as being the Z-split rule mentioned above, and Z-over as being the X-split rule.

Without seeing the definitions for that specific system, that is the most specific answer I can give.

Hope that helps.