The US Open Qualifying Tournament gets underway Tuesday morning as 256 players look to book their place in the final Grand Slam of the year.

There are 32 spots in the main draw up for grabs – 16 for men and 16 for women – with players needing to win three matches to advance to the first round, which starts on Monday, Aug. 29. 

The qualifying rounds take place from Tuesday to Friday, starting each day at 11 a.m. Qualifying is free to the public and affords fans the chance to see tomorrow's stars today.

This year’s qualifying field features some well-known names such as Melanie Oudin, CiCi Bellis and Radek Stepanek. Oudin (pictured above) made a surprise run to the quarterfinals of the 2009 US Open, defeating Maria Sharapova, Elena Dementieva and Nadia Petrova en route to the second week. Stepanek also made the fourth round in 2009, while Bellis, then just 15 years old and ranked No. 1,208 in the world, toppled 12th seed Dominika Cibulkova in the first round in 2014.

A number of today’s top players have competed in past US Open Qualifying Tournaments, including 2014 US Open champion Marin Cilic (2007), Grigor Dimitrov (2009), Kei Nishikori (2010) and Milos Raonic (2010) among the men, and Madison Keys (2012), Petra Kvitova (2007), Karolina Pliskova (2012) and Agnieszka Radwanska (2006) among the women.

In US Open history, only three qualifiers have ever advanced to the quarterfinals: France’s Nicolas Escude in 1999 and Luxembourg’s Gilles Muller in 2008 among the men, and the U.S.’s Barbara Gerken in 1981 among the women. At last year’s US Open, Johanna Konta of Great Britain and Anett Kontaveit of Estonia came close to advancing to the quarterfinals; both reached the fourth round, losing in three sets.

The US Open Qualifying Tournament typically includes players ranked between 105 and 250 in the world. In addition, the USTA awards qualifying wild cards to nine men and nine women. Two of those 18 wild cards are reserved for the men’s and women’s champions of the US Open National Playoffs, the series of qualifying events that opens the US Open to anyone age 14 and over. 

The most recent qualifying wild-card entries to advance to the main draw were Tommy Paul and Jessica Pegula in 2015. In total, six men and 10 women have advanced into the main draw after using a wild card to gain entry to the qualifying tournament.