
Rugby
Share
Published 18:13 19 Mar 2015 GMT
Updated 18:16 19 Mar 2015 GMT

Crucially, the front row players must all drive straight, but by driving at different speeds and forces, it means that one side of the scrum will begin to rotate.
And once it moves past the required 90 degrees, the side not in possession of the ball will be awarded the feed at the next scrum.
However, deliberately creating a wheel through rotating your body is illegal.
On Saturday against Cardiff, Ireland were correctly penalised when Jack McGrath attempted to do this, by taking a step to the left and rotating the scrum on it's spot, before eventually driving forward.

https://youtu.be/ldfDVXjtV1wExplore more on these topics: