Randomly inserted in packs at a rate of one in 25, this 31-card set is autographed by the league's top players. The Ken Griffey Jr. card was actually not available in packs. Instead, an exchange card was printed and seeded into packs. Collectors had until July 27th, 1999 to redeem these Griffey exchange cards. A selection of players were short-printed to 400 or 800 copies. These cards, however, are not serial numbered.