Upper Deck's Pros & Prospects Rare Breed emerged during the brand's peak era of innovation in 2000, when the hobby was exploring increasingly creative ways to celebrate baseball's biggest names. The set represented the kind of premium, limited offering that defined late-90s and early-2000s collecting, blending premium production quality with exclusive player selections that appealed to serious enthusiasts. Ken Griffey Jr. remained baseball's most captivating figure during this period, and his inclusion in this exclusive set captures him at the height of his career dominance. Collectors have long pursued Griffey cards from this era as touchstones of the sport's most electrifying player, making any notable representation from premium early-2000s releases particularly significant to vintage enthusiasts.