General structure

Diagram of a baseball diamond

Baseball is played between two teams of nine players each on a baseball field, under the authority of one or more officials, called 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 four bases. Numbered counter-clockwise, first, second and third bases are cushions (sometimes informally referred to as bags) shaped as 15 in (38 cm) squares which are raised a short distance above the ground; together with home plate, the fourth "base," they form a square with sides of 90 ft (27.4 m) called the diamond. Home base (plate) is a pentagonal rubber slab known as simply home. 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.

Pat Burrell of the Philadelphia Phillies warms up in the On-deck circle as his teammate enters the batter's box (see diagram).

The pitcher's mound is located in the center of the infield. It is an 18 foot (5.5 m) diameter mound of dirt no higher than 10 inches (25.4 cm). Near the center of the mound is the pitching rubber, a rubber slab positioned 60 feet 6 inches (18.4 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.

At the college/professional level, baseball is played in nine innings in which each team gets one turn to bat and try to score 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 in which 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 — a fact that differentiates it from most other team sports. The teams switch every time the defending team gets three players of the batting team 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. 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 thereafter, play stops and the home team is declared the winner.

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. The pitcher throws—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 boxes 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 24" x 6" (~ 61 cm x 15 cm) plate located atop the pitcher's mound — during the entire pitch, so he can only take 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 that signal to the pitcher what pitch to throw and where. If the pitcher disagrees with the call, he will "shake off" the catcher by shaking his head; he accepts the sign by nodding. Each team has a different set of signals, though the number 1 is almost universal as a fast ball. The catcher also usually signals the desired location of the ball within the strike zone as well as "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 the air, tag outs, force outs, and strikeouts. After the fielding team has put out three players from the opposing team, 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". 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 only by batting, then becoming a base runner, touching all the bases in order (via one or more plays), and finally touching home plate. To that end, the goal of each batter is to enable 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 successfully touches home plate without being tagged out after touching all previous bases in order scores a run. In an enclosed field, a fair ball hit over the fence on the fly is normally an automatic home run, which entitles the batter and all runners to touch all the bases and score. A home run hit with all bases occupied ('bases loaded') is called a grand slam.

Baseball around the world

Baseball is largely known as America's pastime, but has a fan base in several other countries as well. The history of baseball in Canada has remained closely linked with that of the sport in the United States. As early as 1877, a professional league, the International Association, featured teams from both countries. While baseball is widely played in Canada, and many minor league teams have been based in the country, the American major leagues did not include a Canadian club until 1969, when the Montreal Expos joined the National League as an expansion team. In 1977, the expansion Toronto Blue Jays joined the American League. The Blue Jays won the World Series in 1992 and 1993, the first and still the only club from outside the United States to do so. In 2004, Major League Baseball relocated the Expos to Washington, D.C., where the team is now known as the Nationals.

The first formal baseball league outside of the United States and Canada was founded in 1878 in Cuba, which maintains a rich baseball tradition and whose national team has been one of the world's strongest since international play began in the late 1930s. Professional baseball leagues began to form in other countries between the world wars, including the Netherlands (formed in 1922), Australia (1934), Japan (1936), and Puerto Rico (1938). After World War II, professional leagues were founded in Italy (1948) and in many Latin American nations, most prominently Venezuela (1945), Mexico (1945), and the Dominican Republic (1951). In Asia, Korea (1982), Taiwan (1990), and China (2003) all have professional leagues.

Many European countries have pro leagues as well, the most successful beside the Dutch being the Italian league founded in 1948. Compared to those in Asia and Latin America, the various European leagues and the one in Australia historically have had no more than niche appeal. Recently, the sport has begun to grow in popularity in those nations, most notably in Australia, which won a surprise silver medal in the 2004 Olympic Games. In 2007, the Israel Baseball League, featuring six teams, was launched. Competition between national teams, such as in the Baseball World Cup and the Olympic baseball tournament, has been administered by the International Baseball Federation since its formation in 1938. As of 2004, the organization has 112 member countries.

Since the early 1970s, the annual Caribbean Series has matched the league-winning clubs from Puerto Rico, Venezuela, Mexico, and the Dominican Republic. The Confédération Européene de Baseball (European Baseball Confederation), founded in 1953, organizes a number of competitions between clubs from different countries as well as national squads. The inaugural World Baseball Classic, held in March 2006, had a much higher profile than previous tournaments featuring national teams, owing to the participation for the first time of a significant number of players from Major League Baseball.

The 117th meeting of the International Olympic Committee, held in Singapore in July 2005, voted not to hold baseball and softball tournaments at the 2012 Summer Olympic Games, but they will remain Olympic sports during the 2008 Summer Olympic Games and will be put to vote again for each succeeding Summer Olympics. The elimination of baseball and softball from the 2012 Olympic program enabled the IOC to consider adding two different sports to the program, but no other sport received a majority of votes favoring its inclusion. While baseball's lack of substantial appeal in much of the world was a factor; more important is the unwillingness of Major League Baseball to have a break during the Games so that its players can participate, something that the National Hockey League now does during the Winter Olympic Games. Because of the seasonal nature of baseball and the high priority its fans place on the integrity of major-league statistics from one season to the next, it would be more difficult to accommodate such a break in Major League Baseball.

Baseball around the world

Baseball is largely known as America's pastime, but has a fan base in several other countries as well. The history of baseball in Canada has remained closely linked with that of the sport in the United States. As early as 1877, a professional league, the International Association, featured teams from both countries. While baseball is widely played in Canada, and many minor league teams have been based in the country, the American major leagues did not include a Canadian club until 1969, when the Montreal Expos joined the National League as an expansion team. In 1977, the expansion Toronto Blue Jays joined the American League. The Blue Jays won the World Series in 1992 and 1993, the first and still the only club from outside the United States to do so. In 2004, Major League Baseball relocated the Expos to Washington, D.C., where the team is now known as the Nationals.

The first formal baseball league outside of the United States and Canada was founded in 1878 in Cuba, which maintains a rich baseball tradition and whose national team has been one of the world's strongest since international play began in the late 1930s. Professional baseball leagues began to form in other countries between the world wars, including the Netherlands (formed in 1922), Australia (1934), Japan (1936), and Puerto Rico (1938). After World War II, professional leagues were founded in Italy (1948) and in many Latin American nations, most prominently Venezuela (1945), Mexico (1945), and the Dominican Republic (1951). In Asia, Korea (1982), Taiwan (1990), and China (2003) all have professional leagues.

Many European countries have pro leagues as well, the most successful beside the Dutch being the Italian league founded in 1948. Compared to those in Asia and Latin America, the various European leagues and the one in Australia historically have had no more than niche appeal. Recently, the sport has begun to grow in popularity in those nations, most notably in Australia, which won a surprise silver medal in the 2004 Olympic Games. In 2007, the Israel Baseball League, featuring six teams, was launched. Competition between national teams, such as in the Baseball World Cup and the Olympic baseball tournament, has been administered by the International Baseball Federation since its formation in 1938. As of 2004, the organization has 112 member countries.

Since the early 1970s, the annual Caribbean Series has matched the league-winning clubs from Puerto Rico, Venezuela, Mexico, and the Dominican Republic. The Confédération Européene de Baseball (European Baseball Confederation), founded in 1953, organizes a number of competitions between clubs from different countries as well as national squads. The inaugural World Baseball Classic, held in March 2006, had a much higher profile than previous tournaments featuring national teams, owing to the participation for the first time of a significant number of players from Major League Baseball.

The 117th meeting of the International Olympic Committee, held in Singapore in July 2005, voted not to hold baseball and softball tournaments at the 2012 Summer Olympic Games, but they will remain Olympic sports during the 2008 Summer Olympic Games and will be put to vote again for each succeeding Summer Olympics. The elimination of baseball and softball from the 2012 Olympic program enabled the IOC to consider adding two different sports to the program, but no other sport received a majority of votes favoring its inclusion. While baseball's lack of substantial appeal in much of the world was a factor; more important is the unwillingness of Major League Baseball to have a break during the Games so that its players can participate, something that the National Hockey League now does during the Winter Olympic Games. Because of the seasonal nature of baseball and the high priority its fans place on the integrity of major-league statistics from one season to the next, it would be more difficult to accommodate such a break in Major League Baseball.

Baseball

Baseball is a bat-and-ball sport played between two teams of nine players each. The goal of baseball is to score runs by hitting a thrown ball with a bat and touching a series of four markers called bases arranged at the corners of a ninety-foot square, or diamond. Players on one team (the offense) take turns hitting while the other team (the defense) tries to stop them from scoring runs by getting hitters out in any of several ways. A player on offense can stop at any of the bases and hope to score on a teammate's hit. The teams switch between offense and defense whenever the team on defense gets three outs. One turn on offense for each team constitutes an inning; nine innings make up a professional game. The team with the most runs at the end of the game wins.

Baseball on the professional, amateur, and youth levels is popular in North America, Central America, parts of South America and the Caribbean, and parts of East Asia and Southeast Asia. The modern version of the game developed in North America, beginning in the eighteenth century. The consensus of historians is that it evolved from earlier bat-and-ball games, such as rounders, brought to the continent by British and Irish immigrants. By the late nineteenth century, baseball was widely recognized as the national sport of the United States. The game is sometimes referred to as hardball in contrast to the very similar game of softball.

In North America, professional Major League Baseball teams are divided into the National League (NL) and American League (AL). Each league has three divisions: East, West, and Central. Every year, the champion of Major League Baseball is determined by playoffs culminating in the World Series. Four teams make the playoffs from each league: the three regular season division winners, plus one wild card team. The wild card is the team with the best record among the non–division winners in the league. In the National League, the pitcher is required to bat, per the traditional rules. In the American League, there is a tenth player, a designated hitter, who bats for the pitcher. Each major league team has a "farm system" of minor league teams at various levels. These teams allow younger players to develop as they gain on-field experience against opponents with similar levels of skill.