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Jerry Hrechka Authentic = Dog ate card, it when through dog's digestive system and came out dog's rear end.
PSA1 - Dog sniffed at card, took it into mouth ,chewed it, swallowed, then regurgitated it
PSA2 - Dog chewed on card, then spit it out.
PSA3 - Dog sniffed at card, pawed it then moved on.
For all grades PSA4 or higher the dog never came near the card.
Hope this helps. 
Picture of self satisfied Chief PSA Dog Grader shown above.