This league consists of 24 teams split into divisions and leagues, as well a 14 season regular season. In League Play, the player creates a team and picks nine players from the entire selection of the backyard kids and pro kids, entering a team into the Backyard Baseball League (BBL). The two teams play against each other on the selected field. Clanky to practice batting), or a 'Single Game.' In a single game, the player chooses between the 14 fields available in the Single Game Window, and may also 'create a team.' The player then takes turn picking team members from a selection of the backyard kids and pro kids, alternating with the CPU. The player can choose between 'Spectator' mode (a simulated game between two generated teams of the backyard kids and pro kids), 'Batting Practice' (a mini-game in which the player can choose a player, and receive pitches from Mr.

There are two primary ways to play: 'Single Game,' and 'Season Play.' Repeatedly clicking on the basepath will make the runner go faster, at the expense of stamina. The only major gameplay change is to baserunning. This game introduces several new fields in addition to the ones from previous games.

Gameplay is largely similar to Backyard Baseball 2001, with most changes being cosmetic.

Players in backyard baseball 2003