Polo taken. The official set of rules and rules interpretations are reviewed and published annually by each country's polo association. Most of the smaller associations follow the rules of the Hurlingham Polo Association, the national governing body of the sport of polo in the United Kingdom, and the United States Polo Association. Outdoor or field polo consists of four to eight 7-minute chukkas, between or during which players change mounts. At the end of each 7 minute chukka, play continues for an additional 30 seconds or until a stoppage in play, whichever comes first. There is a four-minute interval between chukkas
Polo downfield to riders who had broken away from the pack at a full gallop. In the late 1950s, champion polo player and Director of the Long Island Polo Association, Walter Scanlon, introduced the "short form", or "European" style, four period match, to the game of polo. The rules of polo are written for the safety of both players and horses. Games are monitored by umpires. A whistle is blown when an infraction occurs, and penalties are awarded. Strategic plays in polo are based on the "line of the ball", an imaginary line that extends through the ball in the line