events offer various amounts of prize money and the numbers refer to the number of ranking points earned by the winner of a tournament. The Dubai Tennis Championships offer the largest financial incentive to players, with total prize money of US$2,313,975 (2012). These series have various draws of 28, 32, 48 and 56 for singles and 16 and 24 for doubles. It is mandatory for leading players to enter at least four 500 events, including at least one after the US Open. Challenger Tour and Futures tournaments The Challenger Tour for men is the lowest level of tournament administered by the ATP. It is composed of about 150 events and, as a result, features a more diverse range of countries hosting events. The majority of players use the Challenger Series at the beginning of their career to work their way up the rankings. Andre Agassi, between winning Grand Slam tournaments, plummeted to World No. 141 and used Challenger Series events for match experience and to progress back up the rankings. The Challenger Series offers prize funds of between US$25,000 and US$150,000. Below the Challenger Tour are the Futures tournaments, events on the ITF Men's Circuit. These tournaments also contribute towards a player's ATP rankings points. Futures Tournaments offer prize funds of between US$10,000 and US$15,000. Approximately 530 Futures Tournaments are played each year. Women's tournament structure In 2021, the WTA rebranded, resembling the men's tournament series, and also providing extra simplicity for fans and consumers. The numbers do not indicate ranking points, or prize money, but is a system to help define different levels of women's tennis. WTA 1000 The WTA 1000 Tournaments (formerly the Premier Mandatory and Premier 5 Tournaments), are a series of seven tournaments that are part of the second-highest tier in women's tennis. 500 and 250 Series The third and fourth tier of women's tennis tournaments are formed from the WTA 500 Series (formerly Premier 700), with fifteen tournaments, and the WTA 250 Series (formerly International), consisting of thirty tournaments. WTA 125 The WTA 125 Series (formerly 125K Series), is the lowest tier of women's tennis, with fourteen tournaments. Players Professional players Professional tennis players enjoy the same relative perks as most top sports personalities: clothing, equipment and endorsements. Like players of other individual sports such as golf, they are not salaried, but must play and finish highly in tournaments to obtain prize money. In recent