Although different groups of people have different demographics, the general breakdown suggests that Reds comprise 25% of the population; Blues 35%; Whites 20%; and Yellows 20%. A 45-question test assesses one's color, based on whether you answer A, B, C, or D.
In 1926, promoter C.C. Pyle created the first professional tennis tour with a group of American and French tennis players playing exhibition matches to paying audiences. The most notable of these early professionals were the American Vinnie Richards and the Frenchwoman Suzanne Lenglen.
From the beginning of lawn tennis in the 1870s, India rubber, made from a vulcanisation process invented by Charles Goodyear in the 1850s, was used to manufacture lawn tennis balls. Originally tennis balls were made solely of rubber, but the wearing and playing properties of the balls were improved by covering them with flannel stitched around the rubber 'core'.