How do you grade edge wear on 1950's - 80's cards?

[jchcollins]

Just curious the consensus. I have seen in many grading standards, PSA, SGC, the old Beckett - what have you - where edge wear (sometimes described as notching or a ding) - where a piece of the border surface is damaged - even if very lightly - means a card cannot grade above a certain range. Some would say EX-MT, others NM, others depends on the severity. If a card is an 8 or better based on corners and centering, how does light edge wear affect the grade? Not talking rough cuts here, but true edge wear.

I'm asking because with some 60's and particularly early 70's cards - this seems super noticeable. Cards even in 7+ grades from PSA and SGC that I have seen still have some of this wear. They don't necessarily bother me, but just curious as a matter of how edges should affect grading.

Thanks.