Former All Black skills coach Mick Byrne is being credited with the Wallabies' resurgence.
Aussie Byrne, who left the All Blacks following their World Cup defence in 2015, is highly regarded for his rugby knowledge and man management skills.
England coach Eddie Jones says Byrne has made a big difference since joining the Wallabies.
"They're probably the form team in the world at the moment," Jones said.
"There's some really good coaching. Mick Byrne has definitely made a difference as a skills coach. You can see his influence on the team. Their selection has been good, their defence is very good and their set-piece is strong."
When Byrne announced he would be joining the Australians, All Black coach Steve Hansen was not concerned that he would spill his team's secrets to their rivals.
"He's told me he's not going to talk about the All Blacks," said Hansen at the time. "He's a good man, I trust his character and wish him all the best and we'll have a bit of fun when we catch up."
Byrne began working with the All Blacks under previous coach Graham Henry and was involved in three World Cup campaigns over 11 years.
He was heavily involved in catching and ball handling, skills and was credited with helping turn the All Blacks' tight forwards into ball-running machines and superb support players.
The All Blacks, including tight forwards such as Brodie Retallick, Charlie Faumuina, Dane Coles and Joe Moody, amazed a global audience with their skills during the World Cup and Byrne can take a lot of the credit for that.
England are looking for a fifth consecutive win against Australia at Twickenham on Sunday.
Jones is set to recall Owen Farrell and Maro Itoje after they were included in an initial 25-man squad. Both rested for England's underwhelming 21-8 victory over Argentina last weekend as part of Jones' long-term plan to ease the workload of some of his players who are also Lions.
George Kruis, who started against Argentina, as well as Ellis Genge and Alex Lozowski, both of whom came on as substitutes, are among nine players to return to their clubs.
Loosehead prop Joe Marler returns from suspension, while winger Jonny May continues to recover from a hamstring injury.