In the game of rugby union, there are 15 players on each team, comprising eight forwards (wearing jerseys numbered 1–8) and seven backs (numbered 9–15). In addition, there may be up to eight replacement players "on the bench", numbered 16–23. Players are not restricted to a single position, although they generally specialise in just one or two that suit their skills and body types. Players that play multiple positions are called "utility players".

The hooker (who wears the number 2 shirt) is positioned between the two props in the scrum and generally throws the ball into the line-out. After the scrumhalf has put the ball into the scrum, the hookers use their feet to "hook" the ball back and win possession for their team. Hookers generally have a short back and long arms to aid in binding to the props. When the opposition is putting the ball into the scrum, the hooker will either attempt to win the ball or try to disrupt the scrum. Hookers are usually more mobile than the props and are often used to carry the ball up during open play. Only specialist front row players can play hooker; if a team cannot field one for any reason, the scrums will become uncontested.

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