Editing Baseball rules (section)

===General structure===
[[File:Baseball diamond.svg|thumb|right|Diagram of a [[baseball diamond]]]]

Baseball is played between two teams with nine players in the field from the team not batting at that point (the batting team would have one batter in play at "home plate" on the field). On a [[baseball field]], the game is under the authority of several umpires. There are usually four umpires in major league games; up to six (and as few as one) may officiate depending on the league and the importance of the game. There are three ''[[base (baseball)|bases]]''. Numbered [[counterclockwise]], first, second, and third bases are cushions (sometimes informally referred to as ''bags'') shaped as {{convert|18|in|cm}} square in Major League Baseball, or {{convert|15|in|cm}} in other rulesets (including Little League, Babe Ruth, American Legion, and NFHS) which are raised a short distance above the ground. Together with [[home plate]], the fourth "base", they form a square with sides of {{convert|90|ft|1}} called the diamond. Home plate is a pentagonal rubber slab {{convert|17|in|cm}} wide. The playing field is divided into three main sections:
*The infield, containing the four bases, is for general defensive purposes bounded by the foul lines and within the grass line (see figure).
*The outfield is the grassed area beyond the infield grass line between the foul lines and bounded by a wall or fence.
*Foul territory is the entire area outside the foul lines.

The pitcher's mound is located in the center of the infield. It is an {{convert|18|ft|adj=on}} diameter mound of dirt no higher than {{convert|10|in|cm}}. Near the center of the mound is the pitching rubber, a rubber slab positioned {{convert|60|ft|6|in|m}} from home plate. The pitcher must have one foot on the rubber at the start of every pitch to a batter, but the pitcher may leave the mound area once the ball is released. The desired alignment of the field (home plate to second base) is [[Points of the compass|east-northeast]].<!-- rule 2.01 -->

At the college/professional level, baseball is played in nine [[inning]]s where each team gets one turn to [[#Batting|bat]] and tries to score ''[[run (baseball)|runs]]'' while the other pitches and defends in the field. High school baseball plays seven innings and [[Little League]] uses six-inning games. An inning is broken up into two halves where the away team bats in the top (first) half, and the home team bats in the bottom (second) half. In baseball, the defense always has the ball which differentiates it from most other team sports. The teams switch every time the defending team gets three players of the batting team ''[[out (baseball)|out]]''. The winner is the team with the most runs after nine innings. If the home team is ahead after the top of the ninth, play does not continue into the bottom half. When this happens, an X is put on the scoreboard for the home team's score in the ninth inning. In the case of a tie, additional innings are played until one team comes out ahead at the end of an inning. If the home team takes the lead anytime during the bottom of the ninth or of any inning after that, play stops and the home team is declared the winner; this is known as a walk-off.

[[File:Baseball swing.jpg|thumb|left|A batter follows through after swinging at a pitched ball.]]
The basic contest is always between the ''[[pitcher]]'' for the fielding team and a ''[[Batter (baseball)|batter]]''. The pitcher throws ''[[pitch (baseball)|pitches]]'' the ball towards home plate, where the ''[[catcher]]'' for the fielding team waits (in a crouched stance) to receive it. Behind the catcher stands the home plate umpire. The batter stands in one of the [[batter's box]]es and tries to hit the ball with a bat. The pitcher must keep one foot in contact with the top or front of the pitcher's rubber—a {{convert|24|×|6|in}} plate located atop the pitcher's mound—during the entire pitch, so he can take only one step backward and one forward in delivering the ball. The catcher's job is to receive any pitches that the batter does not hit and to "call" the game by a series of hand movements which signal to the pitcher what pitch to throw and where. The catcher also usually signals the desired location of the ball within the strike zone and "sets up" behind the plate or holds his glove up in the desired location as a target.  The catcher's role becomes more crucial depending on how the game is going, and how the pitcher responds to a given situation. Each pitch begins a new ''play'', which might consist of nothing more than the pitch itself.

Each half-inning, the goal of the defending team is to get three members of the other team out. A player who is out must leave the field and wait for his next turn [[at bat]]. There are many ways to get batters and baserunners out; some of the most common are catching a batted ball [[in flight|in the air]], [[tag out]]s, [[force play|force outs]], and [[strikeout]]s. After the fielding team has put out three players, that half of the inning is over and the team in the field and the team at bat switch places; there is no upper limit to the number that may bat in rotation before three outs are recorded. Going through the entire order in an inning is referred to as "batting around" and it is indicative of a high-scoring inning. A complete inning consists of each opposing side having a turn (three outs) on offense.

The goal of the team at bat is to score more runs than the opposition; a player may do so by batting, then [[baserunning|becoming a baserunner]], touching all the bases in order (via one or more plays), and finally touching home plate. A player may also become a baserunner by being inserted as a [[Pinch runner|pinch-runner]]. To that end, the goal of each batter is to enable [[#Baserunning|baserunners]] to score or to become a baserunner himself. The batter attempts to hit the ball into [[fair territory]]—between the baselines—in such a way that the defending players cannot get them or the baserunners out. In general, the pitcher attempts to prevent this by pitching the ball in such a way that the batter cannot hit it cleanly or, ideally, at all.

A baserunner who has successfully touched home plate without being retired (called out) after touching all previous bases  scores a ''[[run (baseball statistics)|run]]''. In an enclosed field, a [[fair ball]] hit over the fence on the fly is an automatic ''[[home run]]'', which entitles the batter and all runners to touch every base and score. On a field with foul poles, a ball that hits a pole is also a home run. A home run hit with all bases occupied ('[[bases loaded]]') is called a ''grand slam''.