Not serial numbered, but in a market flooded with serial-numbered parallels, this stands out as a unique item with a print run worthy of a serial number - just without the stamp. Although not nearly as desirable, there are roughly 2.2× fewer Stadium Club Blue Foils (275) than Topps Chrome Green Refractors (Refractor, Wave, RayWave, Lava, Geometric, Sapphire - 6×99 = 594).
Short Print (1 in 32 packs; 1 in 2 boxes. Print run is 275. Odds of this specific card is 1 in 25 cases) (hobby only)
Fun Math SectionGold Rainbow Foilboard (1/1): 1 in 8,797 packs (hobby only)
Blue Foil: 1 in 32 packs
8,797 ÷ 31.99 = 275