The All Blacks are convinced rugby’s new scrum engagement laws will have the flow-on effect of prising open backline defences.

While much focus leading into first Bledisloe Cup Test in Sydney has been on how the new law will affect the front-row battle, New Zealand’s coaches have been gauging its impact elsewhere.

The law – designed to reduce collapses by removing the collision element – will see both sets of props bind with their outside arms during a “crouch, bind, set” referee call.

All Blacks coach Steve Hansen backs the change, which makes its international debut on Saturday.

He expects teething problems but, ultimately a better scrum contest once both teams adapt.

Their analysis tells them that loose forwards will need to stay bound and push for longer, rather than break quickly onto defence.

The result will be bigger holes to exploit in defensive lines.

“You’re going to get rewarded for scrummaging well. We’re excited by the prospect of what it’s going to bring,” he said.

Putting his technical hat on, Hansen expects the defensive team to have an advantage at most scrums because the attacking hooker will need to focus on hooking the ball, removing his power from the shove.

“The other side are going to have everyone’s feet down and pushing. I think the statements will be made by the team not putting the ball in.”

Loosehead prop Tony Woodcock, who will start his 99th Test, says it is too soon to judge the law’s impact but Saturday’s scrum contest will be won by the team who adapt most quickly.