The term sports memorabilia usually refers to a souvenir, memento, keepsake or token of remembrance that is directly connected to a famous athlete, sporting event or personality. These items are generally collected by fans that find sentimental and/ or monetary value of the item(s). There is no set parameter regarding the amount of items, type of sport, or even the era that an item may reflect. A piece of certain kind may be considered a collectable item.
Items that have been in direct contact with a famous athlete can have significant monetary value. Game used items such as the ball in which Mark McGwire hit his 70th home run of the 1998 season sold for $3 million. The most expensive piece of sports memorabilia ever sold at auction was a New York Yankees baseball jersey that was worn by Babe Ruth during the 1920 season.
Autographed pieces of memorabilia are usually more valuable that non-autographed items. Items that have been personalized (i.e. "To Mark," Best Wishes Travis," or "Happy Birthday John") can add sentimental value. Collectors who are interested in purchasing sports memorabilia often look for a certificate of authenticity. Several companies have developed systems to prove authenticity of game-used or autographed memorabilia, and collectors will generally seek out dealers that offer a lifetime, money-back, authenticity guarantee.
The value of a signed item will generally be relative to the profile of the signer, and the scarcity of similar items. When a hig-profile sports star dies, the value often rises as there will no longer be an opportunity to get more. For example, the death of Muhammad Ali in 2016 has raised both demand and prices for signed Muhammad Ali memorabilia
It could be said that collecting sports memorabilia goes back to the first decades of the 20th century, when many people would collect baseballs from baseball games and many asked Babe Ruth for autographs. As years passed and many other sports stars joined their sports, memorabilia collectors also began to broaden their horizons.
When the NBA, MLB, NHL and NFL began selling their jerseys in stores during the 1980s, game used jerseys also became a hot item among sports memorabilia collectors. Former NBA player Dennis Rodman was famous for taking off his jerseys and throwing them to the stands after his games were over. Michael Jordan is probably the basketball player whose memorabilia is most sought after by collectors.