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Is grading rational?

Posted: Mon Dec 02, 2019 7:33 am
by JNOD
We all know it's subjective but is it rational? I ask after taking a deep dive into the PCGS POP reports.

If you graph the number of coins at each grade relative to the numerical scores you see some really odd trends. The most obvious one is that, between AU55/58 and MS-60, there is an enormous drop in numbers. Between MS-60 and MS-65/66 there is a Gaussian curve with a peak at around MS-63. These two phenomena make no sense in terms of a numerical scale.

1. Easy one first: the Gaussian curve in the MS region suggests that there is a set of coins that we all agree are "mint state" and that the assignment of the coins numerically is random within this group.

2. The drop off between "about uncirculated" (itself an absurdity - the coin is either circulated or it is not circulated) to "mint state" suggests that people are loathe to consider a coin to be mint state and avoid the descriptor so that they can preserve it for things that are truly valuable. Never mind the fact that many AU-58s have far more eye appeal that many/most MS-60s.

I conclude:

1. that numbers serve only to qualify the verbal descriptors which carry much more weight and,

2. most people are buying the holder, not the coin.

Any thoughts coinland?

Re: Is grading rational?

Posted: Tue Dec 03, 2019 7:52 am
by momomomo
NGC almost never grade a coin MS-60. They put MS-61 instead. ICCS never use MS-61. CCCS never use VF-35. PCGS and NGC are the only ones using mid-star MS grades. ICCS never grade above SP/PF/MS 67. There are far more brown MS-64/65 copper coins with NGC and PCGS. A lot of collectors around the world don't even use the Sheldon scale. Ect.

Know your TPGs and buy the coin, not the holder.

Re: Is grading rational?

Posted: Tue Dec 03, 2019 12:41 pm
by JNOD
Interesting - did not know that the numerical scale is named Sheldon! And the final point - buy the coin not the holder - really is key. I feel like this is a major pitfall for amateur collectors.

Re: Is grading rational?

Posted: Fri Dec 06, 2019 6:46 am
by JNOD
Actually, the grading of paper money doesn't appear to use to numerical scale....

http://www.coinsandcanada.com/banknotes-grading.php