Something wrong with set ratings ?

coltgus

I am just getting started on a $5 Indian collection. I only have 4 of the 24 coins so far. Another collector also has just 4 so far. His set is rated higher than mine even though based on grey sheet bid, my 4 are worth 17.5 times his ???. I fully understand the math behind the set ratings but shouldn't the rating have to do with the difficulty of assembling the coins ?

tradedollarnut

PCGS has favored a coin weighting system that can cause such irregularites. The weights are set for the most collectable grade and don't always translate well over the entire grade spectrum. It's an inherent limitation of the simplicity of the formula.

A few years back I showed the example of where an AU58 1873-CC trade dollar [worth $1,500] received over 8 times the set rating points of an MS68 1875-S trade dollar [worth $150,000]. This is due to the former's weight of 10 and the latter's weight of 1 - which doesn't translate well to the fact that the MS68 is the truly [conditionally] rare coin and the AU58 is the [conditionally] common coin.

So, the answer is that you are correct. However it's not going to change so just collect the coins you want and let the set ratings fall where they may.

coltgus

Thank-you for the reply. Your seated dollar collection is one of the greatest numismatic achievements of all time. How long did it take you ?

tradedollarnut

Thanks!

The majority of the coins were acquired over an intense 18 month period. Four sets just happened to come on the market and various other singles did as well. Top grade seated dollars tend to be closely held and thus availability is a real issue. In fact, it was my intention to start a set 5 years ago. I went to the ANA with the desire to buy any eye appealing unc I could find. I came home empty handed....

DMWJR

I spent some time thinking about this when the Registry started. My guess is that PCGS's theory only contemplates comparison of complete sets. It is too difficult to compare and rank all the iterations of incomplete sets, and any world class set would be complete, right?

mrcommem

I think that the ratings of the type sets could be fixed very easily to represent rarity and quality. For instance, using two $3 gold, the 1854 and 1854-D. The first one is of the most common and has a weight of 1 within the $3 gold set. The 54-D is the one of the rarest, having a weight of 8 in the $3 gold set. In the Type Set 1792 to 1964, the $3 gold has a weight of 5 compared to all of the other coins, no matter what $3 coins is. So here is the math.

Overall Weight for coin= (Weight in $3 basic set) X (Weight in Type set) X (the grade)

For 1854 $3 = (1) X (5) X (50)=250
For 1854 $3 = (8) X (5) X (50)=2000

By weighing the coins in this manor both rarity and quality are both represented in type sets. This can be done only once all of the various basic sets are weighted. It can work for type commems just as well.

mrcommem

So, what do you all think of my ratings idea?