Individual sports

Tennis
In 2007, British Journal of Sports Medicine reported over 75 million participants worldwide

Table tennis
300 million table tennis players worldwide

Squash
Squash has more than 15 million. According to well-placed insiders

Badminton
Estimated 150 to 200 million Badminton players worldwide

Pool
40 million players in the United States and 500 million players worldwide

Chess
According to the Chess in the Olympcis Campaign an estimated 605 million people worldwide know how to play chess 285 million play and and 7.5 million are registered players.

Team sports

More than a billion alltogether:
Volleyball players, football players, basketball players, ++.