Billiard games are classified into two types: carom and pocket. Straight rail, balkline, and three-cushion billiards are the most popular carom billiards games. Pocket billiards is played on a table with pockets at each end. Each player has five balls which they can place in his or her own pocket, any of the four ball cages mounted on the table, or allow to drop into the main playing area. The object is to be the first to score a total of fifteen points. The oldest record of a game similar to pool is wastyn, which is thought to have originated in India around AD 500. It was later adopted by sailors as a game to pass the time on ships sailing across the Indian Ocean. In 1770, George III of England introduced the first official rule set for Englishpool. The rules were written by Mr. Thomas Parker of the Royal Academy of Music who is now known as the father of modern pool shooting! Today, pool is one of the most popular sports in the United States. Men and women of all ages play pool regularly at bars, nightclubs, casinos, and even some airports. There are even national organizations that promote the sport of pool: the American Pool League (APL) and the World Pool-Billiard Association (WPA).