Ash and his friends meet Casey, a rookie Trainer.
When Ash first sees Casey's Pidgey, he makes a reference to the first episode, where he also tried to catch a Pidgey himself.
The English dub title is a reference to the popular saying "double trouble" and the baseball term doubleheader.
The baseball teams all seem to be representations of real-life Japanese baseball teams, with the Electabuzz based on the Osaka Hanshin Tigers team, and the teams with Magikarp and Starmie logos representing Hiroshima Toyo Carp and the Yokohama BayStars, respectively.
The shot in which Meowth is crying behind a tree is a reference to the series Star of the Giants, in which the main character's sister is also shown crying behind a tree, as she watches her son and father practice playing baseball.