While it’s against the rules of the game to deliberately create a wheel, a side can legally rotate the scrum, providing both props are driving straight.
In our final live scrum analysis of this Six Nations, we’re showing you how to spot the differences between a scrum that’s correctly wheeled, and one that’s rotated illegally.
The key areas to look out for are the feet and hips of the props, the angle of driving, and centre point of the scrum.
For a scrum to be legally wheeled by a defending side, it must move forward by 90 degrees, to the point that the front rows are now perpendicular to their original starting point.
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.