'One thing I picked up is that Australian players like to take ownership quickly," former Irish technical advisor and forwards coach John Mitchell wrote in his book Mitch - The Real Story.

He went on to note that “they don’t have much respect for authority and constantly challenge you to relinquish your leadership, even when it involves ideas and strategies”.

The impact of Australian culture on tomorrow's respective coaches is a subject I'll return to next week. Leinster's former coaches are on two very different cycles. Would Joe Schmidt have excelled in Leinster prior to Michael Cheika?

Australia's defence is fascinating; both their systems and trust required therein. A powerful, controlled scrum can be devastating on opposition attacking plans. But, tomorrow Ireland can use the scrum to expose Australia defensively especially as they are employ their outhalf Bernard Foley away from the channel forcing their scrumhalf Nick Phipps to overcompensate by getting quickly into the field, thus weakening his inside defensive shoulder. His shoulder is open for attack, especially if the Irish scrum anchors the Wallaby backrow.

Sea change

Speaking of scrums, when monster secondrow Will Skelton arrives there’ll be a big sea change. Interestingly, against France, Rob Simmons switched from tight head second row to lose head putting Skelton behind the Wallaby tight head which is a big weight and power addition over the Irish finishing loose head.

Fortunately, he does have a habit of loosely binding on his partner which ensures a huge gap for his number eight to fill.

Add to this his feet placement, which are miles back and his strength can be depowered very easily making Australia vulnerable to a power drive on their tight head side. Will this all matter? Australia employ a multiphase system of multiple ball carriers (Foley is rarely that receiver) to fatigue oppositions and in the closing quarter as we tire, our set piece is vital to stem any tide.

Overall their scrumhalf is interesting in their armoury.

Scrumhalves often position themselves in the neutral slot behind defensive breakdowns; directing the fatties to each pillar and post. But as he often arrives ahead of the fatties to very hot breakdowns he may step into the empty pillar position; thus requiring another Wallaby to cover his position, at which they are currently poor.

French scrumhalf Sebastien Tillous-Borde attacked a pillar-less openside off a second phase breakdown right on the Wallaby line scoring France’s first try. With Nick Phipps’ compensation tackle for Christian Leali’ifano Australia were down their scrumhalf at their most crucial defensive ruck.

Likewise for Welsh scrumhalf Rhys Webb’s opening try – his opposite man Phipps had drifted infield, off a breakdown, away from the immediate danger. Both tries (from scrumhalves!) were malfunctioning fringe defensive errors in the opening minutes and both times the Wallaby scrumhalf was absent, with no Wallaby reacting. Phipps, generally stands 10 yards deep off the ruck inside the ball but with pace this Wallaby defensive system can be exposed by Ireland. But be warned it will take double figure, fast, error -free phases to expose their fledgling defensive systems.

Much of Australia’s defensive system is to prevent the ball getting outside their last man where they will shoot a wide defender out of the line be that a loose forward or back.

Of course Ireland do this also but our forwards are less likely to make this split second decision; thus less errors. They are also comfortable in cul-de-sacking the ball carrier down blind alleys for inside men to soak up. These line breaks are warmly welcomed by home support but often end nowhere.

Tackle technique

The Australian principles are sound; aggressive line speed, so too their tackle technique and their post-tackle technique is the best in world rugby. Don’t just watch openside Michael Hooper’s rushing over the tackled ball; their all at it!

Rhys Ruddock’s deserved selection brings this Wallaby strength into the fore. Ruddock is no Hooper and his Irish team-mates need to understand that Irish ball, on the deck, is extremely vulnerable to the green and gold flow.

However, I’m not convinced re the positioning of Foley defensively. He is often hidden out of sight at fullback while another player fills the ten slot.

When Ireland get to multiphase and Foley eventually finds himself in the ten slot or wider then Ireland must get him to make defensive decisions under pressure. Just like a fatiguing front five player defending open space he will make errors. When Australian errors arrive, Ireland must capitalise by shifting the ball away into open space with hard gain-line running.

Outside of Hooper their main threat is outside centre Tevita Kuridriani who has the physique and pace to create for Israel Folau who loves to rewind at vulnerable fatties.

But what position Quade Cooper will play on arrival is a real challenge for defensive coach Les Kiss. Either way the key to Ireland's success against Australia's defence is high -tempo low-error rugby and knowledge that of the 205 tackles Australia made against Wales and France, Foley made two. liamtoland@yahoo.com