From box: "An exciting battle of wits for two players! All the thrills of real baseball! Includes special 54-card pack; playing pieces; 5 easy-to-follow charts; 2 scoreboards; score pad; complete rules and strategy by Prince Joli Kansil." Sid Sackson's 'Baseball' (from his 'Gamut of Games' book) may have inspired some aspects of it, but the differences are more significant than the similarities. For example, Grand Slam Baseball! uses the same rotation of two minor suits and two major suits as Kansil uses in his backgammon variant Marrakesh; Sackson's 'Baseball' does not.