Black Star Promos are released by Pokemon to promote everything from movies, events, TV shows and several are specific releases for certain sets. Typically, these promo cards are mass produced, and have insanely high populations. However, they all have one thing in common, it is incredibly difficult to get a 10. Black Star Promos are known for having the lowest gem rates in all of Pokémon. For example, one of the top cards that we used for this series has over 6000 total cards submitted to PSA. As of now, out of 6000 cards, only nine examples graded a 10. PSA 10 Black Star Promos are some of the most collectible cards in the entire hobby due to their extreme scarcity.