<P> The ATP World Tour Masters 1000 (previously known as the ATP Championship Series, Single - Week, ATP Mercedes - Benz Super 9, Tennis Masters Series, and ATP Masters Series) is the third highest tier of annual men's tennis tournament after the four Grand Slam tournaments and the ATP Finals . </P> <P> Results in ATP Masters 1000 events earn players more world ranking points than regular tournaments, though not as many as Grand Slam events or the year - end ATP Finals . Up until 2007, most Masters Series finals were contested as best of five - set matches . Currently, all Masters Series matches (including the finals) are decided in best of three - set matches . </P> <P> Rafael Nadal holds the record for the most singles titles with 32 since the Masters series began in 1990 . Nadal and Djokovic together held all 9 Masters 1000 crowns starting with the 2013 Monte Carlo title through the 2014 Miami title, which was the first time that 2 players possessed all nine of the titles . The Bryan Brothers have won a record 38 doubles titles, all as a team . No player has ever won all 9 singles titles in his career, with Novak Djokovic winning 8, and Rafael Nadal, Andre Agassi, Roger Federer and Andy Murray each winning 7 . In doubles, however, Daniel Nestor and the Bryan Brothers (Bob and Mike) have each won all 9 titles throughout their careers . Djokovic holds the record for 6 singles titles in a year (2015). Additionally, Djokovic and Nadal are the only two players to win four singles titles in a row and Nadal is the only person to complete the feat in the same calendar year when he won Madrid, Rome, Canada, and Cincinnati in 2013 . In doubles, the Bryans have won 6 titles in a single year once (2014) and 5 titles in a single year twice (2007 and 2013). </P> <P> Currently, the following 9 tournaments are part of the series: Canadian Open (Montreal, Toronto), Cincinnati Masters, Indian Wells Masters, Italian Open (Rome), Madrid Open, Miami Open, Monte - Carlo Masters, Paris Masters, Shanghai Masters . </P>

Who has the most atp masters 1000 titles