In baseball, a home run (abbreviated HR) is scored when the ball is hit in such a way that the batter is able to circle all the bases in one play without any errors being committed by the defensive team in the process. In modern baseball, the feat is typically achieved by hitting the ball over the outfield fence between the foul poles (or making contact with either foul pole) without first touching the ground, resulting in an automatic home run. There is also the "inside-the-park" home run, increasingly rare in modern baseball, where the batter circles the bases while the baseball is in play on the field.
When a home run is scored, the batter is also credited with a hit and a run scored, and an RBI for each runner that scores, including himself. Likewise, the pitcher is recorded as having given up a hit, a run for each runner that scores including the batter, and an earned run each for the batter and for all baserunners who did not initially reach base on error, except for the runs scored by any runners who reached base while facing an earlier pitcher are charged to that pitcher.
Home runs are among the most popular aspects of baseball and, as a result, prolific home run hitters are usually the most popular among fans and consequently the highest paid by teams, hence the old saying, variously attributed to slugger Ralph Kiner, or to a teammate talking about Kiner, "Home run hitters drive Cadillacs, and singles hitters drive Fords."
The most common type of home run involves hitting the ball over the outfield fence, or above a line on the outfield fence specifically designed to indicate a home run, in flight, in fair territory, i.e., out of the playing field, without it being caught or deflected back by an outfielder into the playing field. This is sometimes called a home run "out of the ballpark", although that term is frequently used to indicate a blow that completely clears any outfield seating, as a home run is usually automatically assumed to have left the field of play unless otherwise indicated.
A batted ball is also considered a home run if the ball touches any of the following while in flight, regardless of whether the ball subsequently rebounds back onto the playing field:
A home run accomplished in any of the above manners is an automatic home run. The ball is considered dead, and the batter and any preceding runners cannot be put out at any time while running the bases. However, if one or more runners fail to touch a base or one runner passes another before reaching home plate, that runner or runners can be called out on appeal, though in the case of not touching a base a runner can go back and touch it if doing so won't cause them to be passed by another preceding runner and they have not yet touched the next base (or home plate in the case of missing third base).
!-- This section is linked from Roberto Clemente --> An inside-the-park home run occurs when a batter hits the ball into play and is able to circle the bases before the fielders can put him out. Unlike with an outside-the-park home run, the batter-runner and all preceding runners are liable to be put out by the defensive team at any time while running the bases.
In the early days of baseball, outfields were relatively much more spacious, reducing the likelihood of an over-the-fence home run, while increasing the likelihood of an inside-the-park home run, as a ball getting past an outfielder had more distance that it could roll before a fielder could track it down.
With outfields much less spacious and more uniformly designed than in the game's early days, inside-the-park home runs are now a rarity. They are usually the result of a ball being hit by a very fast runner, coupled with an outfielder either misjudging the flight of the ball (e.g., diving and missing) or the ball taking an unexpected bounce. Either way, this sends the ball into open space in the outfield and thereby allows the batter-runner to circle the bases before the defensive team can put him out. The speed of the runner is crucial as even triples are relatively rare in most modern ballparks.
If any defensive play on an inside-the-park home run is labeled an error by the official scorer, a home run is not scored; instead, it is scored as a single, double, etc., and the batter-runner and any applicable preceding runners are said to have taken all additional bases on error. All runs scored on such a play, however, still count.
An example of an unexpected bounce occurred during the 2007 Major League Baseball All-Star Game on July 10, 2007. Ichiro Suzuki of the American League team hit a fly ball off the right-center field wall, which caromed in the opposite direction from where National League right fielder Ken Griffey, Jr. was expecting it to go. By the time the ball was relayed, Ichiro had already crossed the plate standing up. This was the first inside-the-park home run in All-Star Game history, and led to Suzuki being named the game's most valuable player.
These types of home runs are characterized by the specific game situation in which they occur, and can theoretically occur on either an outside-the-park or inside-the-park home run