L'échelle de gradation Sheldon

[AndreT]

Bonjour,

Un peu d'histoire pour débuter.

Source:

http://www.cointalk.com/t39956/

Extrait:

The Sheldon 70 point grading scale
From time to time we see references to the Sheldon 70 point grading scale when talking about the grading system that is currently being used in Numismatics today. For the benefit of those who are not familiar with what Dr. Sheldon did and why he did it, I’d like to offer a short summary.

William H. Sheldon was born in 1898. He first became interested in Early Large Cents at a young age while looking through his Fathers cigar box full of those big old coppers. By the time he was a teenager, he was pricing Early Large Cents for a local dealer and according to him, using a 70 point system. As the years went by he became quite the aficionado of Early Large Cents (those from 1793 through 1814). On three different occasions he assembled sets with the last containing all 290+ known collectable varieties at the time. To put that more into perspective, that collection contained at least 16 (sixteen) 1793 Large Cents! In 1948 he published EARLY AMERICAN CENTS detailing much of his research as well as introducing his 70 point concept to the hobby. (Technically speaking, it’s not even a 70 point system since Dr Sheldon only used 22 of the 70 numbers as compared to the 30 or so in use today.) Although Dr Sheldon is well respected by the numismatic community for his research, if not for his honesty, the general consensus at the time was that the 70 point concept was a “whimsical” idea. In 1958 he published a revised edition and apparently as a lighthearted gesture in response to the criticism renamed it PENNY WHIMSY.

In his 70 point grading system, Dr Sheldon was attempting to equate the value of Early Large Cents by using a numerical grade. To accomplish this he first determined the value of the various Cents in what he called “basal” state. This he defined as “identifiable and unmutilated”. For basal state he assigned the numerical grade 1 (one). Everything from here on is predicated on the basal value. By examining auction records and dealer price lists, along with a little interpretation on his part, he determined that a coin grading “good” was worth four times basal so he assigned the numerical grade 4. For a coin grading “fine” he determined that it was valued at 12 times basal and assigned the numerical grade 12 and so on up to “perfect uncirculated” which he determined to be 70 times Basal. So in effect, the 70 point system was chosen because it provided the multipliers he needed for his system to work (in most cases) with regard to common dates and varieties that were readily available.

If a particular coin was scarce, rare or a rare variety, additional calculations were necessary in order to determine value. This he accomplished by devising a set of 10 “rules” to be applied as needed based on the condition census at that time. For example, rule #5 states “If known to be in the first half dozen but not among the first three, and not full MS, value equals condition times basal times 1 ½”.

In some cases, rule #10 would need to also be applied. “If tied for honors with one or more coins, simply calculate what the total value of these coins would be when placed in descending order of rank as if there were no tie, and divide by the number of tied coins”. What that means is that in some cases, several rules would need to be applied in order to get the desired result.

Of particular interest is the fact that his system was designed for Early Large Cents of 1793 through 1814 and not for the remaining issues of Large Cents, nor any other series of US coins. Even at that, there were certain issues of Early Large Cents where his system would not generate the desired result. Also, the multipliers he determined for the scarce and rare varieties were skewed due to the fact that the information available for condition census coins was very limited at the time. From 1965 to 1990, more than a thousand Condition Census coins have surfaced. For many of the varieties, the finest known in Penny Whimsy would not be in the top six today.

Dr Sheldon was also rather vague in defining what constitutes a certain grade. He assigned three numbers for “good” coins (4, 5, & 6), but only has one description. The same for other adjectival grades on up the ladder. Clearly his objective was not so much to define the grades themselves, but to assign numbers to accommodate his system. Some of his adjectival grades are different than those being used today. In addition to basal for grade 1, he uses very fair for grade 3. The descriptions he offers for the various grades offer interesting reading as well. For example, he defines AU 50 as “Close attention or the use of a glass should be necessary to make out that the coin is not in perfect Mint State. Typically, the AU 50 coin retains its full sharpness but is darkened or is a little off color”. The descriptions for 60, 65 and 70, the only three MS grades he used, are very vague as well. Here’s what he says about MS 60. “For condition 60 a minor blemish, perhaps some microscopic injury, or light trace of discoloration may be tolerated”.

One interesting note is that in his breakdown by variety he lists 9 (NINE) MS- 70’s in the condition census for the 1795 Large Cent!

As you can see, aside from the numbers themselves, today’s numerical grading standards have little in common with Dr Sheldon’s. We can only speculate as to what the current system might look like today had Dr Sheldon needed a multiplier of 93 or 117 for his “perfect Uncirculated”.

[AndreT]

Bonjour,

Oui l’échelle de Sheldon originale contient 70 grades, mais en réalité tous n'ont pas été utilisé dans le passé et ne le sont toujours pas aujourd'hui non plus.

Voici un tableau qui énumère la trentaine de grades utilisés aujourd'hui.

Source:

http://users.hal-pc.org/~canupnet/coin-grading.html

Extrait:

[AndreT]

Bonjour,

Plus près de nous, voici un article intéressant (sur Numicanada). André Langlois, l'auteur de l'article, est vice président numismatique de l'ANPB.

Source:

http://www.numicanada.com/pieces-de-monnaie-articles.php?article=les-hauts-grades&id=284

Extrait:

MS (Mint State) : C'est l'état naturel d'une pièce qui a été produite pour être utilisée en circulation normale ('business strike') mais qui n'a pas (ou pas vraiment) servi : sans aucune trace d'usure (rien n'est effacé ou même le moindrement affaibli), mais généralement avec plus ou moins de marques de surface causées par le contact avec d'autres pièces, notamment lors du processus de fabrication et d'emballage ('bag marks'), et aussi lors de la mise en circulation. Eh oui, 'MS' n'implique pas que la pièce n'ait jamais circulé; en fait elle peut avoir servi pendant quelques jours, pas assez pour qu'il y ait à proprement parler de l'usure, mais disons assez pour que les contacts avec d'autres pièces se multiplient (par exemple quand on casse le rouleau et qu'on le vide dans un tiroir-caisse). Si par la suite un collectionneur la retire de la circulation, disons avant que l'accumulation de contacts ait pu causer un début d'usure, alors la pièce sera toujours considérée non-circulée, mais le grade pourrait alors être MS-62 ou même 60, alors qu'une pièce qui n'a jamais vu le fond d'une poche ni un tiroir-caisse pourrait être MS-63, ou 64, ou même plus dans des cas d'exception. Naturellement même une pièce qui n'a pas circulé une seule minute peut avoir des marques causées lors de sa fabrication; mais il y a toujours une (petite!) proportion de pièces qui « passent entre les gouttes de pluie » et s'en tirent avec très peu de marques, parfois même si peu qu'il faut les chercher à la loupe; dans ces cas on atteindra parfois les plus hauts grades.

[AndreT]

Bonjour,

Comme collectionneur "amateur" ou "Pro" comment faire pour mettre un grade de l'échelle Sheldon sur mes pièces sans faire appel à une entreprise de certification ?

En plus de plusieurs sites, dont Numicanada, qui mettent des photos et descriptions pour chaque grade, il y a des références dans presque tout les livres traitant de numismatique. La plupart indiquent aussi les points d'usures à surveiller.

Il faudra cependant savoir que plus les pièces seront de haut-grades, plus l'exercice demande un oeil averti. Pour les pièces destinées à la revente mais aussi les pièces dont on désire s'assurer de l’authenticité, avec une valeur monétaire ou numismatique notable, l'utilisation d'un service de gradation externe et indépendant comme CCCS, s'avère peut-être un choix et un investissement judicieux selon la pièce.

Personnellement, je vous conseille de vous faire la main, plutôt l'oeil, sur des pièces de moindre valeur monétaire et/ou que vous désirez conserver dans votre collection personnelle. Avant de vendre une pièce que vous avez vous-même évalué, en avertir l'acheteur. Il pourra l'évaluer lui-même ou la faire évaluer par une entreprise de certification si la valeur de la pièce justifie l'investissement. Ça vous évitera sûrement quelques désagréments.

Dans le livre de M.K Blais, il y a un tableau "unique" que j'aime bien et qui pourrait vous aider:

Source:

Price Guide for Canadian Coins Prof. Édition 2012

Extrait:

[Tirelire]

Merci pour cette information.
Moi... qui croyait que Incirculer, voulait dire pas circuler du tout..
comme acheter tout NEUF...

Ca me rassure un peu...car on ne peut pas avoir tous des pièces
incirculées...

[AndreT]

Merci pour cette information.
Moi... qui croyait que Incirculer, voulait dire pas circuler du tout..
comme acheter tout NEUF...

Moi aussi jusqu'à très récemment

Mais si d'autres sources (externes ou officielles) disent autrement, ça serait bien de publier cette source ici dans ce sujet.

Merci

[Tirelire]

J'ai trouvé ceci...

http://numicanada.com/forum/viewtopic.php?t=9312