You have a card you think is special. Maybe it is a vintage holographic Charizard or a modern alt art you pulled from a pack. You want to get it graded, but before you spend $25 to $300 on a submission, you should know what PSA is actually looking at. PSA evaluates four things: centering, corners, edges, and surface. Your final grade is based on the weakest of those four areas. A perfect surface will not save you if your centering is off. This is the most common reason cards miss a PSA 10. Centering measures how evenly the border is distributed on all four sides of the card.