The season-ending event on the men's tennis tour has under-gone many changes since it began in 1970. The 2001 event, which rotates cities, will be on the Olympic court in Sydney, Australia, which is a Rebound Ace surface.

On Dec. 9, 1999, the International Tennis Federation, ATP Tour and Grand Slam Committee announced that the ATP Tour World Championship and Grand Slam Cup would be discontinued and a new jointly owned season-ending tournament, called the Tennis Masters Cup, would begin in 2000.

The field would consist of the top eight players in the standings for ATP Champions Race 2000, a new season-long points race that will determine the year-end No. 1 ranking at the conclusion of the tournament.

That ranking was determined in dramatic fashion in the final match of the 2000 season as Gustavo Kuerten became one of the few men to defeat Pete Sampras and Andre Agassi back to back in a tournament to earn the year-end No. 1 ranking. Marat Safin, favored to end up with the top rank, fell to Agassi in the semifinals. Kuerten defeated Sampras to reach the final, but he still needed the victory against Agassi to pass Safin in the rankings.

From 1970-1989, the season-ending championship tournament was known as the M

asters. It was played at various sites around the world before finding a home in New York at Madison Square Garden in 1977.

Until last year, fields for the season-ending championships consisted of the players who earned the most ranking points during that calendar year.

The first two Masters, in Tokyo in 1970 and Paris in 1971, were played under astrict, round-robin format with a six-man field. Players met each of the other five entrants, with the winner determined by the best overall record.

Stan Smith won the first Masters title in 1970 with a 4-1 record. For the event's first four years, first prize was $15,000.

Ilie Nastase won the 1971 event in Paris with a perfect 6-0 record.

In 1972, the Masters was played in Barcelona and had a slightly different format. The field was increased to eight players and split into two groups of four. Each group played a round-robin, with the players with the two best records from either side advancing to the semifinals. Round Robin matches were best-of-three sets, with the semifinals and finals best-of-five. Nastase won again, defeating Smith in the final.

That format remained in place through the January 1981 event that capped the 1980 season. In 1982, the tournament switched to a single-elimination format with an eight-man field.

Along the way, first prize was increased to $40,000 in 1974 and $100,000 in 1978. The eight-man, two-group round-robin format with semifinals and finals returned in 1986 and is still in use today.

Prize-money distribution also changed in 1986. Each match win was worth a predetermined amount, allowing champion Ivan Lendl to take home $210,000.

In 1990, after the creation of the ATP Tour, the event was moved from Madison Square Garden to Frankfurt, Germany, and became known as the ATP Tour World Championships. The prize money was increased dramatically.

Michael Stich earned $1,240,000 for winning the 1993 title. Pete Sampras and Boris Becker, the winners in 1994 and 1995 respectively, took home $1.225 million. Sampras earned a record $1,340,000 by winning his third season-ending title in 1996, the first time the event was held in Hannover, Germany.

Three years ago, Sampras became only the third player to win at least four world championships and was the first player to win back-to-back world championships since Lendl captured three in a row from 1985-1987.

In 1998, Alex Corretja rallied from two sets down to defeat countryman Carlos Moya and become the first Spaniard to win the event since Manuel Orantes in 1976.

In 1999, Sampras defeated Andre Agassi in straight sets to tie Lendl on the all-time list with five titles at the season-ending event. Nastase has claimed the championship four times and John McEnroe and Becker each have won it three times.