The "no left-handed player" rule was originally implemented during the 1930s, but relaxed around the time following the end of World War II. However, the United States Polo Association reinstated the rule for good in 1974. Polo takes place on horseback and is a team sport. Similar to hockey and soccer, the idea in polo is to score goals, which are located on either end of a polo field. The ball is moved through the use of a long-handled wooden mallet.