Question Regading Weights

Axtell

I just got done going through the 1971 topps baseball set composition, and made a spreadsheet that shows all cards above normal weights (higher series in this set have higher and higher weights) and had a couple questions.

First, I notice a slight bump in weight over the cards in the same series. Is this due to collectors rubber banding teams together, and the teams' card usually on front, thereby reducing the number available in graded quality?

Secondly, where do the weights come from? I assume it's based not only on value, but on desirability? 2 cards garner a '10' weight: Clemente and Mays (both cards are numbered past 600 as well), and the Ryan (numbered 513) gets a 9 weight.

I know the high series of these cards command a premium due to them being scarcer. I just found it an interesting exercise to see what weights were assigned and why.

helionaut

Weights are generally derived from SMR. The price for a common card in 8 is weight one, and they go up from there. Naturally, this doesn't reflect all possibilities, like when a key RC is worth 30 times a common card and is only weight 10, but it's a kind of a sliding scale. Desirability is a function of both the player shown and the scarcity, which is usually tied to the series, the higher numbers generally being scarcer to some degree, and so priced with some premium. A high number common might price at $9 while a first series card prices at $6, so the high series might get a 1.5 weight. A high number card of a top tier star is going to be weighted more heavily than it would be in the first series. Also, keep in mind that weights for the mainstream Topps sets were created years ago now, and sometimes the registry itself has an effect on what's in demand and so weights might not reflect current demands.