[Spartan Warrior]

Yeah, forgot to mention the changes in pass interference rules. Used to be able to ride guys all the way down the field before the Illegal Contact penalty was invented. Now if DBs even breathe on receivers it's a pass interference call.

The changes in how they call unnecessary roughness is big too. Used to be a receiver going over the middle was going to get decapitated. Now you can't do that, so the middle of the field is opened up. You can just go right up the seam in a way you couldn't before without dying.

And then you've got the Shotgun and pistol formations making it easier to pass, improvement in pass blocking, and rules to protect the quarterbacks from all kinds of hits (low hits, high hits, being driven to the ground). Basically every innovation in football in the last 40 years has made it easier to pass.

So if you're creating a period roster, I'd probably do stuff like give the QBs low accuracy, the DBs high press and coverage ability to make it really hard to pass. If it's more of an All-Star roster I'd rate the guys as they'd be as modern football players with the assumption that QBs from the old days could adjust to modern offenses and play efficiently like modern QBs do.