Polo is a team sport played on horseback in both outdoor fields and an indoor arenas. The modern game lasts roughly two hours and is divided into periods called chukkas. Polo is played professionally in 16 countries.  Polo originated in southern and central Asia, most likely as a Persian sport.  Modern polo was popularized by the British but originated in India. The rules and practices of the sport of polo are designed to avoid injury to rider and pony.  The speed and mass of a horse participating in a competition create many instances where collisions and potential serious injury could and do occur, so a very detailed rules set has been devised to eliminate to the greatest extent possible potential injury.  The guiding principle and rule set for modern polo  lends an atmosphere of “gentlemanly” cooperative play and thus the sport earns its moniker as “the sport of kings.”