Question about set rating

mafoliq

I am confused about the way psa grades and rates sets under the registry. Should there be or is there a benefit to having heavier weighted cards in your registry as opposed to commons? If so, it is not reflected in the final set grade. I have small t205 and t206 sets and am not sure if this is a problem with the newer sets.
I am sure PSA wants to reward collectors who spend more time and money to collect the rarer cards in a set, but to do that, I am not sure the math they use is correct. If you have thoughts about this I would enjoy reading them.
I have only made a few posts in the past and enjoy reading everyone's posts and hopefully will contribute more in the future.

Martin

fsjeter

<<Should there be or is there a benefit to having heavier weighted cards in your registry as opposed to commons? If so, it is not reflected in the final set grade. >>

The early benefit is a higher initial set rating if you have more of the heavier weighted cards than commons as you are building the set. Once you reach 100% completion, the set rating and weighted GPA are the same and the grade weight will have a higher increase if the heavier weighted cards have higher grades. That said, if every card in the set was a PSA 8, then your weighted GPA and set rating would be 8.00. If some of your commons were PSA 9's or 7's the GPA would increase or decrease accordingly. The change would be different if the grade weight of the card was higher.

Take the 1887 N28 Allen & Ginter set which only has 10 cards. As stated before, if you built this set in all PSA 7's, the weighted GPA and set rating would be 7.00. Let's assume that every card was a PSA 7 except Charles Bennett (a common with a grade weight of 1) which is a PSA 8. Your set rating and weighted GPA would increase to 7.04. Now, let's make a similiar assumption except instead of Bennett, you have all PSA 7's with a PSA 8 Cap Anson (grade weight of 5). Now you have a set with a weighted GPA and set rating of 7.22. In both cases you have 9 PSA 7's and one PSA 8 but because the PSA 8 is weighted heavier in one instance, the set rating and weighted GPA are higher. If you have excel, I can get you a spreadsheet for your set with the grade weight and rating so you can play with different grades and see how it affects the set rating. I hope this helps and I didn't confuse you too much!

Scott

mafoliq

Hi Scott,

Thanks for the help. Still have some questions that I can't quite figure out. If I can't, I will probably post again this weekend. Again, your example was very helpful.

Martin