Cricket is a bat-and-ball game played between two teams of eleven players on a field with a 22-yard pitch and a wicket at each end, each comprising two bails balanced on three stumps. The aim of the game is to score more runs than the opposition. One player, the bowler, bowls a hard leather ball at speeds of up to 150 kilometers per hour as a player from the opposing team attempts to hit it. Cricket is believed to have originated as a childrens game in the south-eastern counties of England during the medieval period. Although there are claims for prior dates, the earliest definite reference to cricket being played comes from evidence given at a court case in Guildford in January 1597. Cricket is one of many games in the "club ball" sphere that basically involve hitting a ball with a hand-held implement; others include baseball, golf, hockey, tennis, squash, badminton, and table tennis. Cricket is played in many formats, but the most popular are Test cricket and One Day cricket.