How does a mark affect a card's grade?

[JollyElm]

228. Twoplicity
The suppositional rule of thumb that a card with a qualifier should have a monetary/trade value equal to a straight graded card two whole numbers lower.


• The supposed two point drop in grade for a qualifier emanated from the PSA Registry, where a PSA 6 MK would only count as a PSA 4. It's become a rule of thumb, but many of us don't ascribe to that particular theory, and put more consideration into the overall eye appeal (i.e., is the off-centering minor, or is the mark not too blatant?) to determine its value.

• With PSA it is pretty straight forward. If they say a card deserves a grade of X and it has a mark, the result will be a PSA X MK. With other TPGs, it is not so easy to pinpoint what a mark will do to the number grade, or how low it will drive it.

• On a side note (and it's nothing personal, as I'm talking about each and every collector), no one is ever right about the grade they say a card will get, so if you're thinking the 1955 Topps Kaline should be a 6 (sans mark), you should definitely act like it will come back a 4 or 5 to protect yourself, and make an offer to the owner accordingly.

Good luck!!