I use my knowledge of ANA standards. Eye appeal is arguable as Chance mentioned but it can usually be mitigated somewhat - ie, a really bright MS coin that has strong pinwheel luster will normally be graded as a 64 or better while a dull or spotted coin will rarely get past a 63. There are exceptions, however - I have seen many coins prof graded that have high grades but terrible eye appeal (IMO).
You have probably noticed this when looking at grades the site members give when they are weighing in on grading coins posted by other members.
You have probably noticed this when looking at grades the site members give when they are weighing in on grading coins posted by other members.




















