With faith in their defensive system maintained by effective patches, the Wallabies say they're now searching for the "holy grail" of consistency and belief.
But one look at the stats required to win a World Cup shows just how much improvement is needed from the Wallabies' defence to be a legitimate contender in Japan next year.
The Wallabies conceded just 16 points per game as they surged to the 2015 World Cup final, and the defensive bravery shown with 13 men against Wales is in the history books.
Since that tournament, though, Australia’s defence has been inconsistent and the points conceded average has steadily climbed.
The Australian side has let in an average of 27 points a Test, among the highest of the world’s top rugby nations, and this year conceded an average of over 30 in the Rugby Championship.
New Zealand have kept opponents to just 17 points per Test since the last World Cup,
As the man responsible for the defensive effort at the World Cup in 2015, Wallabies assistant coach Nathan Grey doesn't shy away from the need for improvement.
But speaking in Wales ahead of the Spring Tour opener, Grey said the positive moments in 2018 - including a gritty defensive win against South Africa and a tight Ireland series in June - were evidence that the Wallabies have the ability to be a strong defensive outfit.
“There's snippets of all the matches that we've played this year that we can really hang our hat on that defensive performance and say, ‘Okay, that period we're really good,’,” Grey said.
“But we all know at this level, you have to get that consistency and that's something we're working towards and the players and the coaching staff are really driven to achieving that.
Asked where he thought the Wallabies were in their defensive development, Grey was pragmatic.
“Everything's a work in progress for us,” he said.
"Having the players believe in the system and just go out and execute it is something we're searching for and when the guys get that, that consistency's going to be delivered on the park," he said.
"That's the holy grail of coaching trying to get that consistency and that belief amongst the players, so they go out, execute, no inhibitions and really back themselves and when you've got 15, 23 players doing that, you become a really dangerous proposition."
Defence becomes more important than ever when the Rugby World Cup rolls around and the defensive statistics show exactly how stingy teams need to be to hold up the cup.
No country has won the World Cup conceding more than an average of 13 points per game since the tournament's 1987 inception - New Zealand conceded just 10 points per Test in 2015 to win the trophy.
Australia won the 1991 Rugby World Cup conceding an average of just 9.6 points a game and their 1999 trophy came at the expense of 12 points per Test.
World Cup rugby tends to be more restrictive than regular Test matches but the statistic is a telling mark of where the Wallabies' defence needs to be in 11 months’ time.
In the three years prior to the 2015 Rugby World Cup, the Wallabies averaged 22 points per Test.
Ireland, England and Scotland have all been more stingy than the Wallabies since 2015 and Wales’ progress in that area the past two seasons is telling.
The Welsh won seven of 13 in 2016 conceding 25 points per Test but that mark was cut back to 15 points per game in 2017 and they have maintained that since.
The Wallabies' rivals this weekend have won the past six in a row.
When it comes to defensive accuracy, the Wallabies have shown they have the ability to stop teams in their tracks, but then in the same game leak several quick tries, particularly after turnovers.
Grey admitted last year that system tweaks were taking time for players to adjust to and the improvement is beginning to come, albeit slowly.
Their second half in Argentina was one of their most accurate as they conceded just three points in the second half to pull off a record comeback.
The Sydney Bledisloe has become Australia’s aberration in recent seasons, with the Wallabies racking up 40 missed tackles in this year's opener and in 2016's 42-8 loss as well.
Interestingly, however, stats show the side has proven more efficient with their tackles this year than last year, with the Brisbane Ireland Test return of 91 per cent their most accurate return in a match since the 2016 June Series opener against England.
The challenge for Australia, Grey said, is maintaining that kind of accuracy through a whole match, and across an entire year.
“We're certainly taking steps in the right direction around being able to put opposition under pressure when they've got the ball and look to be nice and physical and dominant in that area,” he said.
“But certainly, lots of work to do and we're seeking that consistency.
“We've got our own standards that we really hold ourselves really true to and the players are really focused on achieving those and we're confident that when we hit those consistently we're going to be a very strong side.”The Wallabies take on Wales on Saturday November 10 in Cardiff, kicking off at 5:20pm local, Sunday 4:20am AEDT, LIVE on beIN Sport and SBS.