Wallabies forwards coach and Argentinian international Mario Ledesma thinks the scrum has returned to its glory days as a result of recent law changes.

Ledesma represented the Pumas on 84 occasions between 1996 and 2011 and played more than 200 matches in the Top 14. However he thinks the scrum is a better contest now, than it was for most of his playing career.

“It goes back to what I learnt when I was young in Argentina, because with the new rules we have gone back 20 years in respect to scrums,” he said following Wallabies training in Sydney today.

“The whole technique is highlighted now, the last 10 years it’s been about physical strength, but now we have gone back to technique.

“It’s a good thing for me, it got me a job,” the 42-year-old joked.

Ledesma was recruited by Michael Cheika to fix the Wallabies scrummaging woes leading into this year’s World Cup and whilst he admitted he was happy with his adopted side’s progress, he said the scrum would likely determine Australia’s chances in the UK.

“You will never win a World Cup without a good set piece, particularly the scrum,” he said.

“When you are in a pool with England and Wales and going further into the competition against France, South Africa, New Zealand, it is a massive influence.”

Australia’s set piece was arguably the most positive element of this year’s Rugby Championship campaign, but Ledesma expects the challenge to be far more difficult in pool matches against Wales and England.

If they can overcome that, he has no doubt the Wallabies are good enough to claim an unprecedented third World Cup.

“Not only technically, but physiologically it will have an effect,” Ledesma said.

“If we can beat the northern hemisphere teams in that department, then we’ll go along way.”

The coach said he had no concerns about taking just two specialist hookers away to the UK, with Scott Sio set to act as an emergency replacement if needed.

“We (Argentina) played 1999, 2003, 2007 and 2011 with two hookers and a prop that can play hooker and that is the case this year. I’ve got no issues with that at all.”

Ledesma reiterated that the Wallabies best starting XV would likely start against both Fiji and England in the pool stages and said he agreed that the Fijians were the dark horses in Pool A.

“I hope they (Fiji) get tired against the English and if they can beat them, then even better but hopefully we will be rested and that can be an advantage against them.”

The Wallabies depart for Chicago on Saturday morning.