Should TPG Provide A Rationale As To Why They Gave A + Or -

doubleeagle59: As a diamond grader do you use one number when grading or something closer to the 4 C's (color, cut, clarity, weight)? when determining what you will pay and how you present the gem to your clients?

From what I gather in the comments, grading is not perfect, they don't spend much time doing it, you shouldn't fully trust it, it's inconsistent and you should learn to grade coins yourself. Given these drawback, it seems many question the value of a TPG.

As someone who does buy online and can only see this form of purchasing becoming more popular and prevalent over physically attending auctions/stores, you will need to place some level of trust in someone. I'm not at the point where I am making expensive purchases ($1000+), but I feel safer looking at a a high res photo + TPG, than only a photo. I don't think I would buy a $1000 coin online without more details from a TPG + high res photos. Reading PCGS they seem to have descriptors around Wear, Strike, Marks and Eye Appeal, the foundation is there, now they just need formalize it.

I think coin graders do have some fuzzy grading, like your diamond color with multi-grade overlap to give them some flexibility. For PCGS, "Eye Appeal" and most parts of "Strike" have alternate overlaps across most grades.


This is PCGS's scale mapped out using their descriptions across grades.