Home run
In baseball
Baseball is a bat-and-ball sport played between two teams of nine players each. The aim is to score runs by hitting a thrown ball with a bat and touching a series of four bases arranged at the corners of a ninety-foot diamond...

, a home run (abbreviated HR) is scored when the ball is hit in such a way that the batter
Batting (baseball)
In baseball, batting is the act of facing the opposing pitcher and trying to produce offense for one's team. A batter or hitter is a person whose turn it is to face the pitcher...

 is able to reach home safely
Safe (baseball)
In baseball, a baserunner is safe when he reaches a base without being put out by various ways. While a runner is touching a base, he is usually not in jeopardy of being put out, and is thus "safe" from fielders actions...

 in one play without any errors
Error (baseball)
In baseball statistics, an error is the act, in the judgment of the official scorer, of a fielder misplaying a ball in a manner that allows a batter or baserunner to reach one or more additional bases, when such an advance would have been prevented given ordinary effort by the fielder.The term ...

 being committed by the defensive team in the process. In modern baseball, the feat is typically achieved by hitting the ball over the outfield
The outfield is a sporting term used in cricket and baseball to refer to the area of the field of play further from the batsman or batter than the infield...

 fence between the foul poles (or making contact with either foul pole) without first touching the ground, resulting in an automatic home run.