When Bob Uecker is announcing the Red Sox / Mets game, he states "and that's with three E's". The Red Sox famously lost Game Six of the 1986 World Series to the NY Mets on an error when a ground ball went between first baseman Bill Buckner's legs. That play meant the game was concluded with the Red Sox having 3 errors (abbreviated 3 E).
Jackie Anderson's name and uniform number (24) is a reference to Jackie Robinson, who broke the color barrier by being the first black player in Major League Baseball since segregation began in the late 19th century. Anderson is technically not the first female player, thanks to Leela; Robinson was technically not the first black player, because of a handful of pre-segregation players (most notably Moses Fleetwood Walker and his brother Welby Walker).
This episode comes closest to explaining blernsball, the writers intend to make the sport confusing and so they threw in a few oddities at the end of the episode.
Leela's number 7/8 is a play on the number 1/8 which was the jersey number for midget Eddie Gaedel who played 1 game for the St. Louis Browns. Patkin was coaching at 1st base when Gaedel was walked in his only at bat.