Baseball (ball)

A baseball is a ball used in the sport of the same name, baseball. The ball features a rubber or cork center, wrapped in yarn, and covered, in the words of the Official Baseball Rules "with two strips of white horsehide or cowhide, tightly stitched together." It is 9.00–9.25 inches (228.60–234.95 mm) in circumference, (2.86–2.94 in or 72.64–74.68 mm in diameter), and masses from 5.00 to 5.25 ounces (141.75 to 148.83 g). The yarn or string used to wrap the baseball can be up to one mile (1.6 km) in length. Some are wrapped in a plastic-like covering.

A significant characteristic of the baseball is the stitching that holds together the covering of the ball. After a ball has been pitched, these raised stitches act like wings on a plane, catching the wind and causing the ball to swerve slightly on its way to the catcher. Whether the ball swerves to the right, to the left, downward, or a combination thereof, and whether it swerves sharply or gradually, depends on which direction, and how fast, the stitches have been made to spin by the pitcher. See, for example, curveball, slider, two-seam fastball, four-seam fastball, sinker, cutter.

In the early, mid-1800s days of baseball, there was a great variety in the size, shape, weight, and manufacturing of baseballs. Early baseballs were made from a rubber core from old, melted shoes, wrapped in yarn and leather. Fish eyes were also used as cores in some places. Pitchers usually made their own balls, which were used throughout the game, softening and coming unraveled as the game went on. One of the more popular earlier ball designs was the "lemon peel ball," named after its distinct four lines of stitching design. Lemon peel balls were darker, smaller, and weighed less than other baseballs, prompting them to travel further and bounce higher, causing very high-scoring games.

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