Baseball is a sport that encompasses more than the usual athletic features of performance, competition strategy, and player training and preparation. In the United States, baseball is a part of the social fabric. Baseball is part athletic endeavor and part folklore, defined as much by its place in American culture as by the game itself.

Baseball, played on a triangular shaped playing surface, is believed to have evolved from the English game of "rounders." Rounders was a variation of the sport of cricket, sharing the common features of bases being run by the offensive team and a thrown ball being batted to produce a score. By 1869, it is believed that Abner Doubleday was the first to codify the rules of what would become modern baseball. The recognizable modern elements of baseball include nine players in the field and a diamond-shaped field consisting of home plate and three bases 90 ft (27.4 m) apart. The essence of the game is the confrontation between pitcher and batter, 60.5 ft (18.4 m) apart, with an inning represented by three batters being called out.

Professional baseball and amateur play alike grew in popularity into the early 1900s. The National League was founded in 1876; the rival American League was formed in 1901. The first World Series, named not to signify a world championship, but in honor of the competition sponsor, the New York World newspaper, was first played in 1903. Every small town in America had baseball diamonds and teams. The cloud of illegal gambling and an effort to rig the outcome of the 1919 World Series, known as the "Black Sox" scandal, so named for the Chicago team at the epicenter of the controversy, was regarded as a national disgrace.

The rise of players such as Herman "Babe" Ruth and Lou Gehrig, and the New York Yankees team in the 1920s returned baseball to a positive public light. Baseball was the unquestioned favorite team sport in the United States until the 1950s. Major league baseball was in turn supported by a vast minor professional league structure, from where prospective major leaguers were developed. The nature of the game changed after World War II, as the infamous baseball "color line," an unspoken but well-enforced prohibition against African-American players competing in major league professional baseball, was first crossed by Jackie Robinson, a member of the Brooklyn Dodgers. Other baseball icons were created in the 1950s and 1960s, such as Mickey Mantle, Willie Mays, and Henry (Hank) Aaron. Like the game itself, baseball heroes occupied a place in popular culture unlike other American athletes; there was a name recognition that was bigger than the sport itself.

Until World War II, baseball was only played to any significant degree in North America (the game had enjoyed significant growth in Canada in parallel progression to that in the United States). The wartime presence of U.S. servicemen in countries such as Japan, Australia, the Philippines, Puerto Rico, Venezuela, and the Dominican Republic served to introduce the game to those regions. Today, each of those countries has thriving baseball cultures, with a noticeable presence in the American major leagues. However, baseball is not on the same plane as sports such as soccer, cricket, rugby, or basketball in terms of global sport status. The sport has enjoyed official status an Olympic medal sport since 1992; the International Olympic Committee has determined that the Beijing Olympics of 2008 will be the last such baseball competition.

One enduring international baseball championship has been the Little League World Series, a competition for teams of youths aged 12 and under. Teams from various parts of the world participate in regional play downs for the opportunity to advance to the World Series, held each year in Williamsport, Pennsylvania, at a specially configured stadium.

Modern American professional baseball, which for more than a century was said to be as "American as Mom and apple pie," has undergone significant stresses in recent years. The stoppage of league play in 1994, and the corresponding cancellation of that year's World Series, due to a dispute between the owners of the major league teams and the players union had a significant impact upon the popularity of the game. The widely held concerns regarding whether major league players were routinely taking anabolic steroids or other performance-enhancing drugs, which concerns were the subject of seemingly unending media coverage as well as a United States Senate review, impacted upon the popularity of the game; in the 60 years since the end of World War II, baseball, while remaining popular in absolute terms, has fallen from first place to fourth in American sports culture behind professional football, college football, and professional basketball as a spectator sport.

Baseball has developed a number of variations over the past century. In the United States, baseball is the generic term applied to all varieties of the game. There are different types of competition that involve the batted ball as the chief manner of scoring against an opponent. Baseball, occasionally referred to as "hard ball," is the traditional game, as played in the United States major leagues and throughout the world.

Softball is a distinct form of baseball. The field of play is smaller, and the four bases are 60 ft (18.2 m), as opposed to 90 ft (27.4 m), apart. The ball is larger in circumference and is of a less dense composition than that of a baseball, which makes it much more difficult to hit as hard or as far as a baseball. The pitcher stands 40 ft (12.2 m) from the batter, and the pitch is delivered underhand, in a windmill motion. This game is the most popular women's baseball in the world.

Lob ball, or slow pitch, is similar in its rules and field of play to softball, with the key exception being the speed and trajectory of the ball when it is pitched to the batter. The game is designed to encourage the batter to hit the ball, whereas in all other forms of baseball the pitcher employs the opposite tactic. Lob ball came to prominence in the 1970s in North America as a less-taxing, more recreational and participatory form of baseball.

There are a number of reasons as to why baseball has endured as a part of American sporting culture, and to a lesser degree, as an international game. The first is the absence of time constraint in the competition. Baseball and cricket (from which baseball owes some derivation) are the only team sports where there is no time limit within which the game must be completed. The inning and the "at bat" (the period spent by an individual batter facing a pitcher in an inning) are not regulated by time, but by the result achieved—a hit, a walk, a strike out, or an out in the field. For these reasons, a team can, at least in theory, always come from behind to win a game.

Baseball is also one of the few sports where there is a series of one-on-one encounters that make up the competition. Unlike other team sports, such as football, basketball, soccer, or rugby, in which the team must function in a harmonious unit to achieve a goal, both offensively and defensively, there is a typical baseball sequence: pitcher versus batter; fielder versus runner, when the ball is hit in the field of play; and fielder versus runner, when a base runner attempts to advance on a hit or by a steal. Baseball teams must work together in the field to succeed, however, it is these individual encounters that are at the heart of the game.

Baseball is also noteworthy in the sense of what type of athlete will be most successful in the sport. While hitting a fast moving, spinning baseball with power is aided by the development of powerful muscles, particularly in the arms, shoulders, wrists, and core (lower abdominals, trunk, and thighs), many highly successful hitters rely on exceptional hand-eye coordination, anticipation, and speed to make regular contact with the ball and generate hits.

Defensively, the position of catcher has often lent itself to a larger athlete, due to the often physical contact required of the position. A bigger player is able to better withstand collisions at home plate and foul tips, where the batted ball is directed at high speed backward at the catcher. (It was these dangerous balls that led to the catcher's protective equipment being dubbed the "tools of ignorance.")

In other areas of the game, there is a decided premium on speed and agility. Defensive players such as shortstops, second basemen, and outfielders, and particularly the center fielder, cannot be effective unless they are able to cover significant distances and make split-second decisions as to where the ball must be thrown.

Baseball also combines a unique pairing of objects making contact that gives more dimension to the game. The object of the sport is to strike a round ball with a round bat, contact that frequently produces unusual movement by the struck ball. Baseball has been the subject of many learned dissertations concerning the application of physical principles, such as what causes a pitch to curve (Magnus effect of subtle differences in air pressure on the thrown ball), why an aluminum bat will cause a baseball to travel further than a wooden bat (different coefficients of restitution in aluminum versus wood), or how an outfielder is able to track down a high fly ball (relationship between eyes and the inner ear/balance function).

No sport has adherents that follow the flow of the play with a greater fascination with playing statistics than does baseball. To its devotees, the absence of time limits and the essential battle between batter and pitcher give baseball a cerebral quality.

SEE ALSO Anabolic steroids; Baseball injuries; Baseball strength and training exercises; Softball: Slow pitch vs. the fast pitch.