The eighth spot is reserved, if needed, for a player or team who won a major in the current year and is ranked from ninth to twentieth.

Since 2003, the tournament has used a unique format not seen in other WTA Tour events: the players are separated into two groups of four, within which they each play three round-robin matches.

The top two players or teams from each group after the round-robin stage move on to a knock-out format in the semifinals and final to determine the champion.

The championships were held for the first time in October 1972 in Boca Raton, Florida (USA) as a climactic event at the end of a series of tournaments sponsored by Virginia Slims, called the Virginia Slims Circuit.

The WTA then decided to adopt a January–November playing season, and so the event was switched to being held at the end of each year.

The event was held in Los Angeles, California from 1974 to 1976 before moving to Madison Square Garden in New York City in 1977.

Players earn ranking points on the leaderboard, and the top seven singles players and top seven doubles teams on this leaderboard at the conclusion of the WTA season (as of the Monday following the final regular season tournament) earn the right to compete in the WTA Finals.

In doubles, point totals are calculated by the 12 best results among any of the non-125 WTA tournaments and Grand Slams.

[18] The tables below break down the prize money, participation fees are prorated on a per match basis.