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
History of water polo would let the ball drop in the water first and then reach out for it, but the dry pass made the offensive game more dynamic, and contributed to Hungarian dominance of water polo for 60 years. In 1936, James R. ("Jimmy") Smith, California water polo coach and author of several books on water polo mechanics, developed a water polo ball made with an inflatable bladder and a rubber fabric cover, which improved performance. The previous leather ball absorbed water and became heavier during the game. In 1949, rule changes allowed play to continue uninterrupted after a referee whistled an ordinary