From The Vault
Little Leaguer is a Fallout 3 Perk.
Years as the Vault little league MVP have honed your hitting and throwing. With every rank, you gain 5 points of Melee Weapons skill and 5 points of Explosives skill.
According to a flier in the Vault 101 cafeteria, baseball is played in the Atrium.
While explosives obviously have nothing to do with playing baseball, since the F2 skills "throwing" and "traps" were integrated into "explosives", this perk's influence on the aforementioned skill is probably due to the fact that a player in the pitcher position will be able to throw grenades much more efficiently. this is supported by the fact that while taking the G.O.A.T , marking the "pitcher" option will be counted into a consideration for tagging Explosives (along with cherry-bombing Dad's toilet and Mr. Abernathy's door).