Baseball

The baseball traces its origin to the game of the same name. Modern baseball evolved from the English game of "rounders" in the first half of the 19th century. Alexander Cartwright of New York formulated the basic rules of baseball in 1845, calling for the replacement of the soft ball used in rounders with a smaller hard ball.
Despite its uncomplicated appearance, the baseball is in fact a precision-made object, and one that has often been the subject of heated controversy throughout its history.
Although baseballs have changed very little in this century, either in terms of their physical dimensions or raw materials, some observers have suggested that the balls have secretly been "juiced up" to increase the output of crowd-pleasing homeruns during periods of lagging attendance at major league baseball games. The manufacturers of baseballs and Major League Baseball have steadfastly denied such allegations, however, and no proof of any covert alterations in the ball's design or composition has ever been produced.
An official Major League baseball consists of a round cushioned cork center called a "pill," wrapped tightly in windings of wool and polyester/cotton yarn, and covered by stitched cowhide. Approximately 600,000 baseballs are used by all Major League teams combined during the course of a season. The average baseball remains in play for only five to seven pitches in a Major League game. Each ball must weigh between 5 and 5.25 ounces (141.75-148.83 grams) and measure between 9 and 9.25 inches (22.86-23.49 centimeters) in circumference to conform to Major League standards.
Such uniformity was nonexistent in the early years of baseball's history, when balls were either homemade or produced on a custom-order basis as a sideline by cobblers, tanners and other small business owners. In 1872, the modern standard for the baseball's weight and size was established. The production of balls became more consistent during the remainder of the decade, thanks largely to the demands made on manufacturers by the newly formed National League, the first professional baseball league.
At the turn of the century, the baseball had a round rubber core. This gave way in 1910 to the livelier cork-centered ball, which was itself replaced two decades later by the even more resilient cushioned cork model. The baseball has undergone only one significant change since that time, when a shortage in the supply of horses in 1974 prompted a switch from horsehide to cowhide covers.