 When the Women's Tennis Association was founded, Billie Jean King was one of nine players that comprised the WTA, also referred to as the Original 9, that included Julie Heldman, Valerie Ziegenfuss, Judy Dalton, Kristy Pigeon, Peaches Bartkowicz, Kerry Melville Reid, Nancy Richey, and Rosie Casals.Today, the WTA has more than 2,500 players from nearly 100 countries competing for $146 million in prize money.The 2018 WTA competitive season includes 54 events, including the WTA Premier tournaments (Premier Mandatory, Premier 5, and regular Premier), the WTA International tournaments, the Fed Cup (organised by the ITF), the year-end championships (the WTA Tour Championships and the WTA Elite Trophy), and four Grand Slams supervised by the International Tennis Federation (ITF).