Upgrades v.s. Downgrades

hedgehog847

I always hear everyone talking about bumping and upgrades.

Do you think that TPG's upgrade more resubmissions or downgrade them? If they upgrade more, why? Are grading standards loosening? If they're downgrading more coins, are the standards tightening up? Is this fluctuation in grading standards a cyclical thing which will change in a year or two?

With all of this movement, up and down, why are they so inaccurate to begin with?

~Jim

hedgehog847

ttt

hedgehog847

<-------------- "It's cold in here!"

Yeah, Tyra. I know

~Jim

Artist

My guess is that people don't send in coins for upgrades unless they believe they might upgrade - kind of slants the odds a bit.

Myqqy

It's awful quiet in this thread!

Sandhawk

Let's see if I can answer this...............

No, because, no, maybe, not sure, and no comment

291fifth

Coin collecting's eternal question...just why do you see so many marginal coins in major brand slabs? Grading is nothing but an opinion...

WaterSport

I belive that Hall himself just reported that very few upgrades ever occur which makes you wonder why the myth of "old Green Holders" will almost always upgrade.

WS

DrPete

Upgrades are more common than downgrades because of the potential profit involved when a coin upgrades; profit motivates such action. Downgrades generally are tried for coins that are grossly overgraded and to accept such a mistake costs the grading company money if they, like PCGS, offer guarantees to the grade. I know of very few downgrades of PCGS coins at PCGS, but we all know they occasionally happen. After all, they have graded over 10 million coins.

Upgrades are still not very common as an overall percentage of coins graded.

I have a scientific background and find myself trying to apply some of the principles of statistics to coin grading. For example, many naturally occurring events or items can be shown in a distribution in the age-old bell-shaped curve. Such statiscal curves can be applied in many ways to coin grading. For a given issue of a coin, using large enough sample sizes, the "true" grades of the surviving coins (an attempt to be objective here) will be distributed by a bell-shaped curve with a continuum of grades, including in-between values. However, the standard numeric grades subjectively given to the coin by a coin grader (professional or otherwise) are given as whole numbers. The coins in-between grades are graded up or down from the "true" grade to reach the whole number grade; with the best graders out there the overwhelming majority of coins are graded very close to the "true" grade. The top grading services usually have two to three graders examine each coin which further diminishes the variation in grading.

The key to successful coin grading is consistency and this is achieved through experience and establishing standard grading criteria. As with any subjective endeavor, the attempts are made to minimize inconsistencies.

I think the reputable grading services such as PCGS are doing a tremendous service to the numismatic community in providing high quality grading services.