The only sport at the Games that only women compete at, softball is a lot like baseball and rounders.
It was created many years ago when baseball players wanted to play a form of the game indoors as well as outside.
Each team has nine players and the teams take it in turns to bat and field.
A team scores runs by crossing the last of four bases and has seven innings in which to score runs.
Once three members of a team are out their teams' innings comes to an end.
Even though pitchers throw the ball underarm it still moves really quickly, sometimes around 70mph.
Who are the British hopes?
There is no British softball team at the Games.
Who are the big names?
Softball has only been in the Olympics twice before, in 1996 and 2000, and the USA were champions both times.