Polo is a game played on horseback between two teams of four players each. They use sticks to drive a ball down a grass field 300 yards long by 160 yards wide, and between goalposts 8 yards apart. A score is made by hitting the ball between the goalposts.
The game begins with the two teams of four lined up facing each other in the center of the field. One of the umpires (there are two mounted umpires on the field and a referee on the sidelines) throws the ball in between the teams. Then, with passes to teammates, speed, and maneuvering, each team tries to score as the opponents try to prevent a score.
A game is split into 7 1/2 minutes playing intervals called chukkas. Eight chukkas are played in Argentina, whilst four chukkas are common in Europe. Players will ride several ponies during the course of a match, with each pony allowed to play a maximum of two chukkas in total, and with a chukka break in between.