Table tennis, also known as ping-pong and whiff-whaff, is a racket sport derived from tennis but distinguished by its playing surface being atop a stationary table, rather than the court on which players stand. Either individually or in teams of two, players take alternating turns returning a light, hollow ball over the table's net onto the opposing half of the court using small rackets until they fail to do so, which results in a point for the opponent. Play is fast, requiring quick reaction and constant attention, and is characterized by an emphasis on spin relative to other ball sports, which can heavily affect the ball's trajectory. Owed to its small minimum playing area, its ability to be played indoors in all climates, and relative accessibility of equipment, table tennis is enjoyed worldwide not just as a competitive sport, but as a common recreational pastime among players of all levels and ages. Table tennis has been an Olympic sport since 1988, with event categories in both men's and women's singles, and men's and women's teams since replacing doubles in 2008. Table tennis is governed by the International Table Tennis Federation (ITTF), founded in 1926, and specifies the official rules in the ITTF handbook. ITTF currently includes 226 member associations worldwide. History The sport originated in Victorian England, where it was played among the upper-class as an after-dinner parlour game. It has been suggested that makeshift versions of the game were developed by British military officers in India around the 1860s or 1870s, who brought it back with them. A row of books stood up along the center of the table as a net, two more books served as rackets and were used to continuously hit a golf-ball. The name "ping-pong" was in wide use before British manufacturer J. Jaques & Son Ltd trademarked it in 1901. The name "ping-pong" then came to describe the game played using the rather expensive Jaques's equipment, with other manufacturers calling it table tennis. A similar situation arose in the United States, where Jaques sold the rights to the "ping-pong" name to Parker Brothers. Parker Brothers then enforced its trademark for the term in the 1920s, making the various associations change their names to "table tennis" instead of the more common, but trademarked, term. The next major innovation was by James W. Gibb, a British table tennis enthusiast, who discovered novelty celluloid balls on a