Grading can transform a Pokémon card from a nostalgic keepsake into a high-value collectible. Knowing what graders look for—centering, corners, edges, and surface—can make or break your card’s score.

Pokémon card grading volumes reached record levels, with PSA and CGC setting new highs as trading card game submissions surged past 2.2 million. The boom comes as collectors adopt innovative ...