There’s a line he won’t cross, but the Wallabies plan to tap into Joe Schmidt’s trade secrets on the All Blacks as they bid to end more than two decades of Bledisloe Cup heartache.

New Zealand’s 2023 World Cup assistant coach will square off against his old team for the first time as Wallabies boss in Saturday’s Cup opener and Rugby Championship showdown in Sydney.

All Blacks fans are suitably on edge, despite New Zealand having won their past seven Tests against Australia and not lost in Sydney since 2015.

One of world rugby’s great thinkers, Schmidt first linked with the All Blacks as a selector in 2021, before working as a strategist and attack coach for 20 Tests under Ian Foster between mid-2022 and last year’s World Cup in France, where New Zealand lost the final to South Africa.

Schmidt and the Wallabies’ esteemed New Zealand native scrum coach Mike Cron have intimate knowledge of the All Blacks system and will look to use the intel to their advantage at Accor Stadium.

Wallabies forward coach Geoff Parling candidly admits the hosts will “of course” draw on such inside knowledge.

“Look, it’s about how we can improve and what we can do, but it would be stupid not to use some of the knowledge we have of their players and systems,” Parling said on Wednesday.

“Of course we would.”

Schmidt, though, said he would “try to draw a line” when he first accepted the call from Rugby Australia and agreed to take over from Eddie Jones as Wallabies coach.

“It’s an awkward one for me,” he said before the start of the Rugby Championship, noting that the inside knowledge goes two ways.

“That is a conundrum that you face whenever you shift (camps) and with the amount of transitions that occur in international rugby.

“But even in club rugby, you often end up a foe to your friends somewhere along the line.

“And I don’t think I have a massive amount of IP, but I’ve got a lot of experiences after 20-plus years of professional coaching, and whatever I know about the All Blacks, the All Blacks know lots about me as well.

“Even the All Black coaching staff, some of them are good friends … so a lot of those guys know me inside out as much as I know some of what the All Blacks have been doing.”

Schmidt suspected the Wallabies would have learnt as much about the All Blacks from watching Scott Robertson’s side in their opening four Rugby Championship outings, which yielded two defeats to South Africa and one win from two Tests against Argentina.

While the All Blacks will be smarting from the rare successive losses to the Springboks, the Wallabies are backing up from their 67-27 collapse against the Pumas in Santa Fe.