I had a gif of it (maybe someone else scale) somewhere, but I can sumarize?

MS = Mint State 90-100 (go figure how you can have ten grades of "new"?)
AMS = Almost Mint State (almost new, 80-89)
XF = Extra Fine 70-79
VF = Very Fine 60-69
FN = Fine 50-69
VG = Very Good 40-49
GD = Good 30-39
US = Used 20-29
PR = Poor 10-19
DM = Dammaged 1-9

The problem I see is New is 90-100, that's ten grades of new? Followed by ten grades of almost new. OK then there are 30 grades of Fine, followed by 20 grades of Good, 10 used and 10 more poor and 9 degrees of dammaged.

Somehow it's easier to look at chips, which are plastic, not coins, and say they are new, like new, slightly used, used, worn and poor. Six levels of condition, (which may be too many) and the description of the chip says what's important. Warped, drilled, canceled, chipped, Etc.

I like "stands on edge", because it's easy. Pass/Fair no hedging. Although some chips when new, won't stand on edge. But you can tell that if it has a relativly sharp edge with the comment.

Won't stand on edge? It's used or worn or poor. Easy.

SGS seals with a label, so it's not secure. Anyone with a poket knife and two cents worth of brains can open it and change the chip or token. The same guy who grades, is selling them. Conflict of interest.

Grading leads to over grading and the biggest problem with slabbed chips, is you can't touch them or inspect them, you put absolute trust in the grading company.

Remember the grading offers no guarentee of value. It's just an opinion on a little piece of paper, sealed in a piece of plastic. With perfect replicas and repairs, how can they certify that it's authentic or original. You can't even open it and check.