Posted By:
HankronMy second last point. While it will far from solve everything and won't work cleanly all the time (800 1970 Topps low # commons or "I can't remember, I got these with I was seven"), I do not think it would be a bad thing for graders to require the disclosure of the provenance of the card, if even only as a formality. Provenance can be as simple as, "I bought this from 2003 MastroNet auction, lot#3000" or "I bought this autograph directly from Mike Gutierrez and here's a copy of my receipt."
If you took a Salvador Dali to Albert Field, the most famous expert on Dali in the world, he would require you to disclose where you go it. If you took took an Andy Warhol screenprint to have it authenticated by his estate, they would have you document where you got it-- and if you refused to tell them, they wouldn't look at the print.
Naturally, accurate and substantial documentation of provenance doesn't substitute for proper examination, but it does facilitate a better and more assured opinion. Proper examination takes into consideration all relevant information concerning the item, and provenance is always important information.