[benjulmag]

Provided,

1. The grading company has adequate documentation to verify the provenance, and
2. The provenance dates the card to a time there was little financial incentive to alter, and
3. (I) The person from whose collection the provenance refers to and the dealer who then sold the card were people who could be trusted not to alter, or (II) the provenance refers to a high condition find for which there was little reason to alter, then

the provenance could mean a great deal.

A poster example would be the Rosen find of high number 1952 Topps Mantles. A card from that find has a much greater chance of being in its unaltered state than any other high grade '52 Mantle. As the price differential between 8's and higher and the rest of the field continues to skyrocket, I believe in time, if not already, documented Rosen find Mantles will sell for a premium.

To the point that how does one know that the dealer who sold a prominent collection did not alter the cards, the answer is that we probably don't. As such, unless the card was sold directly by the collector, and that person was of such integrity that he/she was not the kind of person to alter cards, provenance in that case probably means little in terms of having confidence the card was not altered.