What criteria does PSA use to "certify" an autograph as authentic?
I ask this because I happened to see this "Certified Authentic" Billy Sullivan autograph for sale on eBay:
http://www.ebay.com/itm/Billy-Sulliv...YAAOSwrklVFbWS and, as his grandson, I can tell you that I don't think I've ever seen him sign his name like that. He always signed it Billy, not Bill, and usually with much more flourish. Here's are two examples of what his signature ordinarily looked like
http://www.ebay.com/itm/VINTAGE-BASE...AAAMXQxKxSBohN and
http://www.ebay.com/itm/1941-DIZZY-T...MAAOSwu4BVjx~q.
So I'm just curious what would make PSA think it is authentic.