Hockey is a stick and ball game with origins dating back thousands of years. It is traditionally played on grass, but more often it is played on synthetic surfaces.Two teams compete using 'hooked' sticks to hit, push, pass and dribble a small, hard ball with one aim in mind - to score a goal by getting the ball past the goalkeeper.
There are 11 players on the pitch with up to five substitutes on the side-line. Players can substitute virtually at any time and any number of times.
Every team has a goalkeeper - although, rarely, a team will play only with field players to put more players into attack. The other 10 players are called 'field players', and are in three categories - attackers, midfielders and defenders.
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