Construction varies. Generally the core of the ball is cork, rubber, or a mixture of the two, and is sometimes layered. Around that are various linear materials including yarn and twine, sometimes wool is used. A leather cover is put on, in two pieces, and stitched together using 108 stitches of waxed cotton thread which is typically red in color. Rolled stitching is flatter and creates less air-resistance. This is the type of stitching used for major league balls and is ideal for the game and everyday play. Official Major League balls sold by Rawlings are made to the exact MLB specifications (5 ounces, 108 stitches) and are stamped with the signature of Commissioner Allan "Bud" Selig on each ball.

 

 

Cushioned cork cores were patented in the late 19th century by sports equipment manufacturer and former baseball star A. G. Spalding. 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 jump off the bat faster, and go 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 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 keep clean, undamaged balls in play.

 

In 1909, sports magnate and former player Alfred J. Reach patented the cork-center baseball, which was adopted by the major leagues the following season. Charles Webb Murphy, owner of the Chicago Cubs, discovered a substance called "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 the ball Reach patented, 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."

 

Throughout the 20th Century, Major League Baseball used two different baseballs, American League and National League. In 2000, Major League Baseball switched to one singular baseball for both leagues. It should be noted that the baseballs were identical in every way except that American Leagues had "Official American League" and the AL President's signature in blue ink, and National League baseballs had "Official National League" and the NL President's signature in black ink

 

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.