Serialization is a staple of the sportscard world, where cards are often numerically stamped to make them more fun to open, and more attractive to collectors. A cool looking basketball or hockey card is one thing, but a rare card stamped “1/75”, denoting the first card in a limited series of just 75 copies? That’s even cooler. Some incredibly rare variant cards may even have a “1/1” stamp, meaning the card’s entirely unique.