On the evidence of the past fortnight New Zealand would beat Australia by 20 points if Saturday's game was anything other than a World Cup final. Every four years the All Blacks come under suffocating pressure to win one match. And only one match.

Otherwise, that entire cycle is seen as a failure.

Nine of the 23 that featured against South Africa experienced this pressure in 2011 but that 80 minutes at Eden Park isn’t something they look back upon with fond memories. The collective performance was nowhere near their expected standard. That’s because they came up against a French side with nothing to lose and enough quality to win two knockout games.

When do the All Blacks only ever score eight points? In a World Cup final.

That same scenario comes around again on Saturday and it’s an even more dangerous proposition given their opponents are Australia.

Besides one or two explainable blips, New Zealand have played the most wonderful rugby in the four years since that night in Auckland.

At this tournament they have been trying to recreate that same pressurised environment. It seemed to hinder their performances during the pool stage but that's because they were focusing on specific elements of their game, knowing full well, as Steve Hansen even stated, that they would beat Tonga, Namibia and Georgia.

But, really, you can't recreate the feeling that will weigh down on them at Twickenham. Australia are complete underdogs yet, in contrast to France four years ago, they are playing a cohesive and intelligent brand of rugby under Michael Cheika.

Ordinary

And look what South Africa managed to do to New Zealand. There were moments last Saturday when the All Blacks looked ordinary. That’s because the Springboks forced them to commit numbers to the breakdown.

There are plenty of moments when three or four black jersey had to fly into a ruck to deny a turnover. All of a sudden they had the same issues Ireland had against Argentina; they were attacking with 11 players against 14.

There are certain elements to New Zealand’s play that make them so effective.

They use the same move over and over again. Off-the-top lineout ball to Ma’a Nonu, who carries up the middle, knowing he will more often than not get over the gainline, with the alternative option of going wide further softening the defence. Once the soft shoulder is identified they have a numerical advantage.

Now, take that away from them, drag them into rucks, as Francois Louw did, and they no longer look like the all-conquering All Blacks. They look like any team under pressure.

It’s about matching their physicality.

That presents Hansen with a huge tactical decision. Do they remain true to their wide game and risk being exposed to turnovers at the breakdown from David Pocock and Michael Hooper or adopt a more territorial approach?

Both Pocock and Hooper are better than Louw over the ball.

Persisting with the wide game will see Dane Coles, their pacy hooker, and Jerome Kaino staying in the wide channels all the time. You see Coles chasing down kicks like a winger. He throws the ball into the lineout and stays put. This ploy gives Julian Savea or Nehe Milner-Skudder licence to roam and burst onto an offload from whoever gets over the gainline.

It also means they keep their width. But that wide, wide game of theirs mightn’t be sufficient to win a World Cup final. Again, this is different to any other game they have played since 2011.

South Africa dragged them into a brutal, one-score fight but I never felt they would lose because of the ease with which they scored their two tries, and so long as Dan Carter was on the field they seemed to be in control.

Carter has not been this good since the 2005 Lions tour. He is playing the best rugby of his life because, like Paulie O’Connell in the Six Nations and right up to the injury, he knows the end is coming. It’s a liberating feeling to know these are your last few games to perform in an All Blacks jersey.

But Australia have the enormously effective presence of Pocock who, more so than Israel Folau, showed against Argentina how important he is to his side.

His mere presence on the field is similar to the O’Connell factor for Ireland in that he makes the other seven forwards perform better. He adds leadership, guarantees the line speed and he does so much damage at the rucks he targets that Hooper knows he must do similar at the next breakdown. The same way O’Connell’s presence would galvanise Peter O’Mahony.

The ripple-effect is evident everywhere. It gifts Bernard Foley the space to look as good as Carter. Foley has become a fine outhalf but he's not in the same league.

Carter is the complete player. See his static position and lack of space when he pulled that drop goal out of thin air last weekend. Nobody is at that level, but with the quick ball generated by the Wallabies pack against Argentina, Foley was able to fling that big skip-pass out for Adam Ashley-Cooper’s first try.

Directed affairs

During the Scottish game, when Pocock wasn’t there and the pack were struggling, Foley lacked influence, whereas Carter directed affairs when New Zealand were in a similar bind; Carter’s tactical kicking, his passing, his defending were all on the money against South Africa.

He did what had to be done.

Matt Giteau can be that man for Australia. He needs to be. Giteau alleviated the pressure on Foley in the second half against Scotland.

He knows when to pass into the space or kick behind. There isn’t a better second five eight in the world.

Ma’a Nonu is just a brilliant player. Sometimes you just hold your hands up and admire great play. For Beauden Barrett’s try last Saturday, New Zealand pressure created a two-on-two situation in the wide channel but Nonu’s fantastic footwork made Damian de Allende break stride, which created a horrible situation for JP Pietersen.

Once de Allende stalled, Pietersen was faced with a lose-lose situation. He may as well have been invisible. If he steps in, the ball goes instantly to Barrett; if he stays off, he won’t catch Barrett in the corner.

That was one of the game's best ever centres performing at his absolute peak. Even if de Allende shoot up, I bet Nonu steps him and scores. Or offloads to Barrett. Remember, this man is keeping Sonny Bill Williams on the bench. He can do all of that.

But Cheika will have noticed when South Africa attacked New Zealand they looked vulnerable. The mentality was to bash them and launch Bryan Habana over the top of Milner-Skudder, which worked twice, but once the Springboks got on the front foot they needed to attack the space they had created.

Yet they couldn't help themselves. Since the Japan game the mentality has seen a complete return to traditional values. The overwhelming power game meant they refused to allow their naturally creative players – Handré Pollard and Willie Le Roux – to play heads-up rugby.

On 12 minutes, when their maul inched New Zealand backwards, Fourie du Preez went to the sky and Habana leaped over Milner-Skudder. A perfectly executed ploy, but what did they do next? Bashed up their huge men – Lood De Jager, Schalk Burger, De Allende and Duane Vermeulen – before a handling error slowed their momentum. Then Burger again carried close in.

It took until the seventh phase for Le Roux to get the ball at first receiver. By then, all they could do was keep bashing up and eventually Read won a turnover.

Le Roux was barely in the game and that’s a shame, but the rationale is understandable: South Africa were prepared to live and die by their tactics.

Australia’s execution, when opportunities arise, should be better.

New Zealand were happy to let South Africa have the ball so long as it was inside their territory, and attack their set-piece. It was calculated rugby, risky even, because if South Africa scored in those last 10 minutes the momentum shift would have been enormous.

New Zealand dared South Africa to build an 80-metre score. By 70 minutes, when Patrick Lambie finally booted them up field, they had expended so much energy to get there they couldn't find another gear to even create a drop-goal opportunity.

More mistakes due to the rain allowed Carter to direct play back into South Africa’s 22.

He employed a very smart, long kicking game and they backed their defence to deliver. Which it did. But that endeavour must have taken its toll.

This World Cup has shown us that whichever squad arrives in the final in the best physical shape will win it.

Argentina, like Ireland before them, wilted before our eyes. Juan Martín Hernández was targeted by the Wallabies. Pocock smashed him with a fair tackle after five minutes and he was eventually forced off. Thereafter, the Pumas began to unravel physically, possibly because they put so much into reaching the semi-finals, with Juan Imhoff and then Agustín Creevy limping off.

Australia are also beginning to struggle. Pocock, Hooper and Scott Fardy were bloodied and bandaged by the end. Giteau and Folau both limped off. Scott Sio was badly missed in the scrums.

New Zealand’s strategic concession of penalties is so clever. They constantly flirt with the offside line, which is a nightmare for the officials as so many bodies creeping offside creates an optical illusion of being onside.

When Pollard got the ball, he constantly had McCaw right in his face. Yet the ball wasn’t in the air long enough for McCaw to be onside.

Strictly enforced

They were caught a few times – and it cost six points – but the promise of the hindmost foot rule being strictly enforced at this tournament is happening less and less as we go deeper into the knockout stages.

Another thing that might hurt New Zealand as we go from quarters to semis to final is it becomes less about risk-reward rugby and more like the cautious, strategic Six Nations approach.

Cheika can tell his players to drag New Zealand into the realm of doubt and they’ll have a real chance. This is a one-off game and anything can happen. They must attack the All Blacks. A World Cup final is pretty good place to play the game of your life too.

It’s a wasted four years if New Zealand lose this game. That’s why the All Blacks are under more pressure.

The Wallabies challenge is clear: produce an error-free performance and wait for doubt to manifest itself in New Zealand minds. Then strike with accuracy.

France did it four years ago and we saw how badly the All Blacks struggled. A lead of 8-7 is a terribly stressful one to be hanging onto. If the doubt starts to spread, if Australia can avoid conceding an early try, then the playing field should level out.

All men can be forced to doubt themselves when put in an environment they are not accustomed to being in.

New Zealand do have a superior bench. Sonny Bill Williams’s two massive carries and the impact of the other subs last weekend was enough to edge the semi-final their way.

That and Carter’s ability to control matters should be enough.

But all of that might cease to matter because it’s a World Cup final.

Anything can happen. Pressure is an unsympathetic enemy.