A tennis shirt, now commonly called a polo shirt and also known as a golf shirt, is a T-shaped shirt with a collar, typically two or three buttons down a slit below the collar, and an optional pocket. A zipper may substitute for buttons, or neither may be present. Polo shirts are usually made of knitted cloth (rather than woven cloth), usually pique cotton or, less commonly, silk, merino wool, or synthetic fibers.History of the tennis shirtIn the nineteenth and early twentieth centuries, tennis players ordinarily wore "tennis whites" consisting of long-sleeved white button-up shirts (worn with the sleeves rolled up), flannel trousers, and ties.As one might expect, this attire presented several problems for ease of play and comfort on the court.René Lacoste, the French 7-time Grand Slam tennis champion, decided that the stiff tennis attire was too cumbersome and uncomfortable. He designed a white, short-sleeved, loosely knit piqué cotton (he called the cotton weave jersey petit piqué) shirt with an un-starched, flat protruding collar, a buttoned placket, and a longer shirt-tail in back than in front (known today as a "tennis tail"; see below), which he first wore at the 1926 U.S. Open championship. Beginning in 1927, Lacoste placed a crocodile emblem on the left breast of his shirts, as the American press had begun to refer to him as "the alligator", a nickname which he embraced.Lacoste's design mitigated the problems that traditional tennis attire created:the short, cuffed sleeves solved the tendency of long-sleeves to roll down the soft collar easily could be loosened by un-buttoning the placket the piqué collar easily could be worn upturned to block the sun from the neck the jersey knit piqué cotton breathed the "tennis tail" prevented the shirt from pulling out of the wearer's trousers or shorts In 1933, after retiring from professional tennis, Lacoste teamed up with André Gillier, a friend who was a clothing merchandiser, to market that shirt in Europe and North America. Together, they formed the company Chemise Lacoste, and began selling their shirts, which still included the small embroidered crocodile logo on the left breast