自责分（Earned Run，通常记为ER），在棒球比赛里指的是对方的得分当中，因为投手的投球所造成的部份（也就是扣除因为失误或是捕逸所造成的失分，但暴投失分会被计算在内）。如果不纯粹是投手投球的错，就称为非自责分（Unearned Run）。纵使发生失误的是投手自己，也不算是投手的自责分（当然，这个失误会纪录在投手的守备数据中）。

自责分主要的用处是配合总投球局数来计算投手的自责分率。

官方纪录员在判定自责分的时候，必须回顾这一局的每一球，设想如果没有发生失误（包括捕手的妨碍打击或捕逸）会有什么结果。如果有疑虑的话，通常会给投手比较有利的判定。

In baseball, an earned run is any run that was not necessarily enabled by a fielding error or a passed ball. In other words, an unearned run is one run that would not have been scored without the aid of an error or a passed ball committed by the defense, and an earned run is simply one that is not unearned. An error made by the pitcher in fielding at his position is counted the same as an error by any other player.