It is the Association of Tennis Professionals, responsible for the mens tour and world rankings of male tennis players.
Novak Djokovic is the top male tennis player on the ATP rankings.
Katerina Vankova, CZE
Science Major: Association of Tennis Professionals
Professional tennis players' rankings will not change until the Monday following the end of the given tournament. This is to allow the ATP (men's tour group) or WTA (women's tour group) time to enter the scores into their respective computer systems, which then calculates the new rankings. This also allows for unexpected delays, such as might be caused by weather, darkness, etc. The media may speculate as to what a player's ranking will be following an event and prior to the release of the latest rankings, but, obviously, that is not official.
ATP stands for Association Tennis Pro, which is made for men's professional world class tennis players. Hope this helps!
Novak Djokovic currently has 16,785 points in ATP rankings, tell me if it was useful or not.
As of March 11, 2013; Andy Murray is the top ranked British player and also the 3rd best player in the world according to the ATP World Tour rankings. He is the currrent U.S. Open and Olympic tennis champion. Andy is also the Wimbledon and Australian Open runner-up to date.
ATP and WTA rankings are updated once every week
ATP World Tour
A player losing in the final of any of the 4 major championships will receive 1200 ranking points in the ATP rankings system.
ATP Tour Championship Tennis happened in 1994.