When judging a coin's long-term future potential, I evaluate every coin in these three areas, based on my experience, knowledge, and expertise.

Why are these three questions so vital?

Based on my experience, over the long term, the more attractive a coin for its respective date, the higher quality the coin for its respective date, and the rarer it is in its respective grade & level of eye-appeal, the more it may likely appreciate in value in the years to come! To coin an old phrase, as true today as it was 200 years ago, “The cream always rises to the top.”

The CVI is a simple, three number rating at the end of each coin description. Examples:

A 1958 Jefferson Nickel PCGS PR68DCAM merits a 1-1-2.
A brilliant 1949-S Franklin Half NGC MS 65 merits a 3-3-12.
A brilliant 1953-D Franklin Half PCGS MS 64 FBL merits a 4-4-13.

The first number in the CVI establishes the relative eye-appeal of a coin for its respective date. The numbers span from 1 (ultimate eye-appeal) to 10 (poor eye-appeal), with 5 being the median. This number is by nature somewhat subjective. Degree of cameo contrast (in the case of proof or SMS coins), relative attractiveness of any color toning (in the case of mint state and proof coins), luster, noticeable marks or spots, are major factors when considering this first number.
Grade is a secondary factor in determining this first number. The emphasis is eye-appeal – the immediate gut reaction one gets when viewing the coin. How does it compare in eye-appeal to other examples of its date? How striking is its appearance? Does it command attention when placed next to other coins within its date and series?

The second number in the CVI establishes the relative quality of a coin for its respective date. The grade of the coin would be used to establish this second number. This second number also extends from 1 (ultimate) to 10, again with 5 being the median.  A coin will receive a “1” if it is either highest grade, or if there are at most 2 examples graded higher. A “1” therefore represents a coin that is either the highest grade for its date, or has no more than 2 examples higher.
Eye-appeal is a secondary factor in determining this second number. The emphasis is grade – how does this coin compare in grade to other examples of the date, from that grading service (NGC or PCGS)? Two coins of the same grade of a given date could conceivably be given a different rating if one example is perceived to have better eye-appeal than the other. For example, a beautifully toned 1955-P PCGS MS66 FBL could receive a “1” for the second number, as it is 1 of 76 examples, with none having been graded higher. Another 1955-P PCGS MS 66 FBL with unattractive toning and dull surfaces might be given a “2”, since, while it is also highest grade, there may be several examples of that same grade with superior eye-appeal.

The third number in the CVI utilizes “The University Rarity Scale” as derived by David Bowers (see below). The third number estimates the absolute rarity (not the latest grading service population numbers!!) of a coin for its respective date in the same grade or higher, with similar or superior eye-appeal. Using this index, 1 represents ultimate rarity – a unique coin. The index extends down to 26.

IMPORTANT: THIS LAST NUMBER IN THE CVI MAY BE ONLY LOOSELY RELATED TO CURRENT GRADING SERVICE POPULATION NUMBERS. For example, in modern coins, PCGS shows only 96 1986-S Jefferson Nickels graded in PR69DCAM, none higher. This coin would not be given an “8” rating, though its population in this grade is between 65 and 124 coins, which corresponds to a URS 8. My estimate, based on my experience with modern U.S. proof coins, is that approximately 20% of the examples in proof sets could grade PR69DCAM, meaning as many as 500,000 examples could conceivably exist in PR69DCAM. This coin would therefore receive a “20” for the third rating.

A coin with a third number ranking 6 or under (between 1 and 32 coins in existence the same grade or higher) must be considered unique to very rare in absolute rarity. A coin with a third number of 7-9 (33 to 249 coins in existence the same grade or higher) would be considered rare. 10-11 (250-999 coins the same grade or higher) would be extremely scarce. 12-15 1,000 to 15,999 coins the same grade or higher) would be scarce to semi-scarce. 16-18 (16,000 to 124,999 coins) would be relatively common. 19 or higher (125,000 or more coins the same grade or higher) would have to be considered very common.

Also, to receive a “1” for this category, a coin must be the highest grade for its issue.

Comparing five 1955-P Franklins, their CVI, and what it means:

 
THE R & I COIN VALUE INDEX IS DESIGNED TO BE STABLE AND UNCHANGING OVER TIME, THOUGH MINOR ADJUSTMENTS MAY OCCUR!
 
New “discovery” coins surface on rare occasions demanding these small adjustments. For example, at one time the finest known 1886-O mint state Morgan was a MS64DMPL. Such a coin would have been 1 of only 2 or 3 examples. The coin might have been given a rating of 1-1-3. Then came Wayne Miller's wonder 1886-O, which PCGS subsequently graded MS67DMPL!! A phenomenal, virtually flawless black & white cameo. Now the finest known, and unique! The Wayne Miller coin is a 1-1-1. The other 1886-O in MS64DMPL would now be a 2-1-4. The first number becomes a “2”, as there is obviously another 1886-O in existence setting a new, higher standard for eye-appeal for that date. The MS64DMPL 1886-O still would have a “1” as the second number, because there is only 1 example of finer quality, with more eye-appeal. The third number may bump to a 4 since, while there are a total of only 4 examples grading MS64DMPL or higher, there is likely to be at least a couple additional examples surfacing over the next decade or two of equal or higher grade. MOST IMPORTANT: The new rating for the MS64DMPL 1886-O does not mean it is now worth less!! The value of the coin must be considered in context with other coins of its relative quality and rarity.

Please bear in mind estimating eye-appeal is subjective and represent this author's opinion. Other people may disagree regarding the eye-appeal of a particular coin. As a result, small changes in any of the three categories being rated may change under review by the author.

As a general rule, if you are assembling a top quality Registry set (there will be many exceptions to this guideline), the first number for any coin you acquire for your set should be a 1 or 2. The second number should also be a 1 or 2. For 1971 and earlier proof coinage, the third number should generally be 11 or less. For later proof coinage, this number may be higher, given the greater availability of later issues in PR69DCAM.

On the other hand, if your goal is to simply acquire attractively priced investment grade coins, the first number for any coin you acquire for your collection should be rated 1-4. The second number should also be rated 1-4. For 1971 and earlier proof coinage, the third number should be 13 or less.

THE  UNIVERSAL  RARITY  SCALE
Devised by Q. David Bowers, originally appearing in his book “Silver Dollars & Trade Dollars Of The United States” published in 1993.