Unearned Run
A run that would not have scored without an error or a passed ball, excluded from the pitcher's earned run average.
An unearned run is one that only crossed the plate because of a defensive mistake. The scorer reconstructs the inning as it would have gone with clean defense, and any run that would not have scored in that version is unearned.
The reconstruction is the hard part and the reason this is a judgment call. If an error should have been the third out, every run scoring after it in that inning is unearned, even runs driven in by clean hits, because the inning should already have been over.
The purpose is fairness to the pitcher. A pitcher who induces three ground balls and watches two get booted has not pitched badly, and their ERA should not say otherwise.
Runs scoring on a passed ball are unearned; runs scoring on a wild pitch are earned. That asymmetry catches out most new scorekeepers.
Bleacher Notes reconstructs the inning to work out which runs would have scored with clean defense, so ERA reflects the pitcher's own work rather than the defense behind them.
What makes a run unearned?
A run is unearned when it would not have scored had the defense played the inning cleanly. Errors and passed balls are the usual causes, and any run scoring after what should have been the third out is unearned.
Do unearned runs count in the score?
Yes. They count fully toward the game's score and toward the batter's RBI. The only thing they are excluded from is the pitcher's earned run average.
Let the scorebook keep itself.
Bleacher Notes scores every play from a single spoken sentence, applying these rules for you. In beta now, free for parents.