At my level scrums usually collapse by accident. Remove scrum resets when no infringement occurs (e.g. There is nothing more dangerous in the game of Rugby Union than the collapsed scrum. We practice good posture etc against a machine but largely left to figure it all out among ourselves mid match. If the prop 'hinges' at the waist, causing a collapse, he is to blame. There are two ways to ensure a scrum cannot collapse. 1. The first is to have the two packs of forwards engage gently while in an almost upright position with their upper torsos well above their hips. Rowly Williams writes If a prop's outside elbow is pointing towards the ground, causing his opposite number to go to ground, that is a penalty too. Our data show that in community-level rugby, ∼6% of scrums result in collapse, compared with ∼50% in international rugby. Rugby union has not been so hard-nosed, and has let the crooked scrum feed creep into the game, even though it contravenes the laws of the game. Front rows with a weak second row or facing a much bigger scrum might try to collapse the scrum rather than lose ground. "As elite referee manager at the RFU Ed Morrison points out, 'Referees don't collapse scrums, players do'." Rugby union has not been so hard-nosed, and has let the crooked scrum feed creep into the game, even though it contravenes the laws of the game. If the prop 'hinges' at the waist, causing a collapse, he is to blame. The engagement of the scrum has been one of the most troublesome areas of the international game in recent seasons, with a high proportion of put-ins leading to free-kicks, penalties or re-sets. The referee blows as a scrum collapses during the Lions tour to Australia in June (Getty Images) If a prop's outside elbow is pointing towards the ground, causing his opposite number to go to ground, that is a penalty too. Eight hunking great forwards (many sporting flattened noses and cauliflower ears that advertise their experience of scrums) on one team collide, head on, with an equal number of monstrously-sized opponents from the other team in an attempt […]

It takes some will to maintain a strong, stable scrum, so I feel like a lot of teams give up on that when the other scrum is punishing them. This one's what I always think of when an international side is penalized in the scrum. Normally if a prop goes to ground due to the opposite scrum being highly dominant (assuming his opposite number did not pull him to the ground) then it will be a penalty against him. a collapse) Instead of a reset, the referee would award a free-kick to the team who had the put-in to the scrum.