Scrum
A scrum is a way of restarting the game safely and fairly after a minor infringement. It is awarded when the ball has been knocked or passed forward, when a player is accidentally offside, or when the ball is trapped in a ruck or maul with no realistic chance of being retrieved. A team may also opt for a scrum if awarded a penalty. It is also awarded to the passing or kicking team if the ball hits the referee.
A scrum is formed by the eight forwards from each team binding together in three rows. The front row consists of the two props (loosehead and tighthead) either side of the hooker. The second row consists of two locks and the two flankers. Behind the second row is the number 8. This formation is known as the 3–4–1 formation. The two packs of forwards engage with each other so that the heads of the front-rowers are interlocked with those of their opponents. Front-rowers always aims for the gap to the left (as they see it) of their opponent. The two locks in the second row bind directly behind the front row with their heads between a prop and the hooker. The flankers bind either side of the locks, and the number 8 binds behind and between the two locks.
Once a scrum is formed the scrum-half from the team awarded the feed throws the ball into the gap between the two front-rows known as the tunnel. The two hookers then compete for possession by hooking the ball backwards with their feet, while each pack tries to push the opposing pack backwards to help gain possession. The side that wins possession transfers the ball to the back of the scrum, where it is picked up either by the number 8 or by the scrum-half. Either the scrum half or the number 8 can then pass, run, or kick the ball and normal play then resumes. A scrum has to be awarded between the 5 metres (16 ft) lines along the goal-lines and touch-lines. A team may also score a pushover try from a scrum; once the ball has crossed the goal-line during a scrum an attacking player may legally ground it.
Scrums are one of the most dangerous phases in rugby, since a collapse or improper engage can lead to a front row player damaging or even breaking his neck. For this reason, only trained players may play in the front row to help avoid injuries. If a team is without sufficient specialist front row players, for example because of injury or sin-binning, all scrums may be "uncontested scrums". In this situation, the packs engage, but do not push, and the team that still puts the ball into the scrum must win it without effort.
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