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 leather. It is 9 to 9 inches (229–235 mm) in 1⁄4circumference (2–3 in or 73–76 mm in 7⁄8diameter). The yarn or string used to wrap the baseball can be up to one mile (1 1⁄2 km) in length. Some are wrapped in a plastic like covering.
Cushioned wood cores were patented in the late 19th century by sports equipment manufacturer Spalding, the company founded by former baseball star A.G. Spalding. During World War II, rubber centers from golf balls were used, due to wartime restrictions on the domestic use of materials. In recent years, various synthetic materials have been used to create baseballs; however, they are generally considered lower quality, and are not used in the major leagues. Using different types of materials affects the performance of the baseball. Generally a tighter-wound baseball will leave the bat faster, and fly farther. Since the baseballs used today are wound tighter than in previous years, notably the dead-ball era that prevailed through 1920, people often say that the ball is "juiced". The height of the seams also affect how well a pitcher can pitch. Generally, in Little League through college leagues, the seams are markedly higher than balls used in professional leagues.
In the early years of the sport, only one ball was typically used in each game, unless it was too damaged to be usable; balls hit into the stands were retrieved by team employees in order to be put back in play, as is still done today in most other sports. Over the course of a game, a typical ball would become discolored due to dirt, and often tobacco juice and other materials applied by players; damage would also occur, causing slight rips and seam bursts. However, after the 1920 death of batter Ray Chapman after being hit in the head by a pitch, perhaps due to his difficulty in seeing the ball during twilight, an effort was made to replace dirty or worn baseballs.
In 1909, sports magnate and former player Alfred J. Reach patented the cork-center based "ivory nut" in Panama and suggested it might be even better in a baseball than cork. However, Philadelphia Athletics president Benjamin F. Shibe, who had invented and patented  the cork centred ball, commented, "I look for the leagues to adopt an 'ivory nut' baseball just as soon as they adopt a ferro-concrete bat and a base studded with steel spikes.". Both leagues adopted Shibe's cork centred ball in 1910.
The official major league ball is made by Rawlings, which produces the stitched balls in Costa Rica. Rawlings became the official supplier to the majors players in 1977, succeeding Spalding, which had supplied the official ball for a century. The cover of the ball was traditionally horsehide through 1973, but due to dwindling supplies cowhide was introduced in 1974. Attempts to automate the manufacturing process were never entirely successful, leading to the continued use of hand-made balls. The raw materials are imported from the U.S., assembled into baseballs and shipped back.
Throughout the 20th Century, Major League Baseball used two technically identical but differently marked balls. The American Leagues had "Official American League" and the AL President's signature in blue ink, whilst National League baseballs had "Official National League" and the NL President's signature in black ink. In 2000, MLB reorganized its structure to eliminate the position of league presidents, and switched to one singular baseball for both leagues. Under the current rules, a major league baseball weighs between 5 and 5 ounces (142 and 149 g), and is 9 to 1⁄49 inches (229–235 mm) in circumference ( 1⁄42–3 in or 73–76 mm in diameter). 7⁄8 There are 108 double stitches on a baseball (which some people call 216 stitches).
Today, several dozen baseballs are used in a typical professional game, due to scratches, discoloration, and undesirable texture that can occur during the game. Balls hit out of the park for momentous occasions (record setting, or for personal reasons) are often requested to be returned by the fan who catches it, or donated freely by the fan. Usually the player will give the fan an autographed bat and/or other autographed items in exchange for the special ball.
Famous baseballs 
There are several historic instances of people catching or attempting to catch baseballs:
- The ball that Mark McGwire hit for his 70th home run of the 1998 baseball season, then setting a new record, was sold by a fan to Todd McFarlane for $3.2 million at auction. (US).
- Larry Ellison, not to be confused with the software entrepreneur of the same name, famously retrieved both Barry Bonds's 660th and 661st home runs.
- Steve Bartman interfered with a play while attempting to catch a foul ball, causing the Chicago Cubs not to get an out in "The Inning" during the NLCS. The loose ball was snatched up by a Chicago lawyer and sold at an auction in December 2003. Grant DePorter purchased it for $113,824.16 on behalf of Harry Caray's Restaurant Group. On February 26, 2004, it was publicly exploded in a procedure designed by Cubs fan and Academy Award winning special effects expert Michael Lantieri. In 2005, the remains of the ball were used by the restaurant in a pasta sauce. While no part of the ball itself was in the sauce, the ball was boiled and the steam captured, distilled, and added to the final concoction.
- Barry Bonds' 73rd home run of the 2001 season. It was the last home run of his historic, record breaking season where he broke Mark McGwire's single season home run record. Ownership of the ball generated controversy and litigation resulted between the two people that claimed to have caught it. The story was made into a documentary, Up for Grabs.
- Barry Bonds' record-breaking 756th home run, beating Hank Aaron's record, caught by a Mets fan in 2007.
- Derek Jeter' 3,000 hit, a home run, was caught by a Yankees fan who gave the ball back to the Yankees and was rewarded with about $70,000 worth of gifts and memorabilia.
See also 
- Cricket ball—ball as used in cricket of similar construction (cork center wrapped tightly with string and encased in leather).
- Juiced ball theory
Notes and references 
- US Patent 932911, Shibe, Benjamin F., "Base-Ball", issued 1909-08-31
- Major League Baseball: "Official Rules : Objectives of the Game", Major League Baseball
- Schneider, Jason (2006-07-04). "All-American mud needed to take shine off baseballs". The Florida Times-Union. Retrieved 2009-10-06.
- Matuszewski, Erik. "Jeter Fan Who Returned Baseball Leaves $180,000 on Table to Do Right Thing". Bloomberg. Retrieved 10 February 2012.
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