South African Gold Coin Exchange.
There were two Evaluation systems for Proof Krugerrand.
The Old Evaluation System (OES) gained wide recognition and proved vital for the need to produce a quantitative evaluation system. Although it was probably the most thorough if its kind in the seventies it was more meticulous than it needed to be and the evaluation took too long.
The OES had a scale up to 35.
The new system called the S.100 was started in 1975.
The South African Gold Coin Exchange accordingly designed the S100 to be re-assessing, simplifying and regrouping all the various aspects of the O.E.S.
The system was based on a starting value of 100 points, to which is added merit points for good frosting, fields and landings (rims) and deducting points from the total for the negative point. It had specific values for specified flaws.
Having been based on the original system, the final point values can be related directly to one another, and a table of these values is given in the S100 booklet. Indeed, it would present no problem to translate the point system to wider categories used by various other dealers trading Proof Krugerrand's.
The result is that the S100 is easier to understand and simpler and quicker to apply, so that any interested person, even without any numismatic knowledge, can now reasonably accurately evaluate Proof Krugerrand in less than ten minutes per coin, once he has acquainted himself with the booklet.
The idea of using quantitative grading or evaluation systems to indicate, specifically in terms of a definite number of merit points, the relative degree of excellence of a coin is now very common with American Numismatic Society's Sheldon system and the improved Steve Ivy system
The O.E.S. certification service was described as the most important achievement of the South African Gold Exchange limited, because without it, it would have been impossible for the inexperienced investor to buy Proof Krugerrand without running the risk of purchasing a proof like or polished UNC Krugerrand or an under-graded coin at a too high price.