number of events that last two weeks, the others being the Indian Wells Masters and the Miami Masters. Currently, the Grand Slam tournaments are the only tour events that have mixed doubles contests. Grand Slam tournaments are held in conjunction with wheelchair tennis tournaments and junior tennis competitions. These tournaments also contain their own idiosyncrasies. For example, players at Wimbledon are required to wear predominantly white. Andre Agassi chose to skip Wimbledon from 1988 through 1990 citing the event's traditionalism, particularly its "predominantly white" dress code. Wimbledon has its own particular methods for disseminating tickets, often leading tennis fans to follow complex procedures to obtain tickets. The international tournament began in 1925. Men's tournament structure Masters Series The ATP Masters 1000 is a group of nine tournaments that form the second-highest echelon in men's tennis. Each event is held annually, and a win at one of these events is worth 1000 ranking points. When the ATP, led by Hamilton Jordan, began running the men's tour in 1990, the directors designated the top nine tournaments, outside of the Grand Slam events, as "Super 9" events. In 2000 this became the Tennis Masters Series and in 2004 the ATP Masters Series. In November at the end of the tennis year, the world's top eight players compete in the ATP Finals, a tournament with a rotating locale. It is currently held in London. In August 2007 the ATP announced major changes to the tour that were introduced in 2009. The Masters Series was renamed to the "ATP Masters 1000", the addition of the number 1000 referring to the number of ranking points earned by the winner of each tournament. Contrary to earlier plans, the number of tournaments was not reduced from nine to eight and the Monte-Carlo Masters remains part of the series although, unlike the other events, it does not have a mandatory player commitment. The Hamburg Masters has been downgraded to a 500-point event. The Madrid Masters moved to May and onto clay courts, and a new tournament in Shanghai took over Madrid's former indoor October slot. As of 2011 six of the nine "1000" level tournaments are combined ATP and WTA events. 500 and 250 series The third and fourth tier of men's tennis tournaments are formed by the ATP 500 series, consisting of 11 tournaments, and the ATP 250 series with 40 tournaments. Like the ATP Masters 1000, these