The 1991 Denny's Grand Slam hologram baseball card set was produced by Upper Deck. The 26-card standard-size set contains one player from each major league team, who was selected on the basis of the number and circumstances of his grand slam home runs. These cards were available at Denny's only with the purchase of a meal from the restaurant's Grand Slam menu; each card came sealed in a plastic bag that prevents prior identification. It is estimated t… [Read More]

The 1991 Denny's Grand Slam hologram baseball card set was produced by Upper Deck. The 26-card standard-size set contains one player from each major league team, who was selected on the basis of the number and circumstances of his grand slam home runs. These cards were available at Denny's only with the purchase of a meal from the restaurant's Grand Slam menu; each card came sealed in a plastic bag that prevents prior identification. It is estimated that two million cards were printed. In 1991, if the contest card was a winner, the collector was entitled to a free meal. By the end of the contest, almost half the teams had hit grand slams during the length of the contest. So many teams hit grand slams in that time frame which caused Denny's never to run that aspect of the promotion again. [Collapse]