Backrow balance will be one of the trigger points for the All Blacks, Springboks, Wallabies and Pumas this weekend as they launch into their search for a place in the 2015 World Cup showdown, reports Wynne Gray.
Kieran Read, Richie McCaw and Jerome Kaino
That's a combined total of 293 test caps between these All Blacks who were at the core of the side's triumph in the 2011 final.
There's the incomparable pedigree of McCaw who has changed his game down the years to deal with lawmakers and rivals and at the same time led his side into more than 100 combats.
He's been there done everything but McCaw has never let complacency seep into his work. He will treat this test with the same concentrated purpose he brings to every contest.
Read's form has wavered this year and there have not been the same sure handling and damaging runs we saw several seasons ago. Maybe he's under instructions to work harder on the inside and let others break free or else he's biding his time.
Any doubts about the punishment Kaino can deliver were dispelled when he flexed his power against France. He's the least capped of the trio but his hammer defence and strong running lines make him the equal in every other department.
Duane Vermeulen, Francois Louw, Schalk Burger
These guys are in the contact business. Loads of it and then some as they look to damage their opponents. They might appear to be solely looking for wrecking ball chances but they also have offloading skills which create havoc when they use them.
Vermeulen's deft backhand flick to his captain Fourie du Preez clinched the Boks' quarter-final win against Wales, while his control and ability to absorb punishment at the back of a reversing Boks scrum is valuable.
He appears to be working into his best form after neck surgery meant he was a marginal pick for the tournament. Louw plays for Bath where his crossover work between open and blindside flanker has made him a favourite as it has done for his Springboks coach Heyneke Meyer.
He carries the Pickard christian name after his legendary Springboks grandfather Jan Pickard, is strong over the ball, is a rugged defender and carries powerfully but has not been in a winning side after nine tests against the All Blacks.
Burger's reincarnation is stupefying. He needed neck surgery in 2006 and a year later was part of the Boks' World Cup-winning side.
He was part of the 2011 World Cup group but two years later after surgery on a cyst near his spinal cord, he contracted bacterial meningitis and there were fears he would not survive.
Last weekend he made an amazing 26 carries against Wales while his work on defence never stopped. Burger's influence with the Boks matches Richie McCaw for the All Blacks.
David Pocock, Michael Hooper, Scott Fardy
When Michael Cheika started this trio against the All Blacks this year in Sydney, there was scoffing this side of the Tasman. What was he thinking playing twin opensiders with Pocock out of position in the boot of the scrum.
That re-arrangement would not cut it against the more conventional All Blacks setup who were up with the best in the world. At the final whistle, when the All Blacks looked at a 27-19 defeat and the impact the Wallaby trio had in that result, they knew they had problems.
Cheika created more curiosity when he began Pocock from the bench in the return leg in a disjointed effort.
At this World Cup, Pocock has been a massive force with his turnovers topping the charts before calf damage meant his absence from the heart-stopper with Scotland. Hooper, too, missed a match after one of his over-zealous charges into a ruck against England.
He is ultra-fit and a match for any opensider with his speed to the breakdown and tackles creating havoc. If Pocock is fit, he and Hooper can operate as a menace either side of the field or in tandem to rattle any rivals.
The glue comes from Fardy, who has been used as a mobile lock by the Brumbies but is best suited to blindside for the Wallabies where his lineout work and defensive reads connect the loose trio.
He was playing in Japan until the 2011 tsunami wiped out the fishing village where he lived. He returned to Australia and was picked up by the Wallabies two years later. His form has been one of the keys to the team's success.
Leonardo Senatore, Pablo Matera, Juan Martin Fernandez Lobbe
There is a shade of uncertainty about this group, nothing to do with the quality of their play but there are questions about their fitness.
Another regular loosie Juan Manuel Leguizamon was injured and could not play in the quarter-final triumph against Ireland while Lobbe did not train earlier this week.
Leguizamon is vastly experienced with a massive workrate which would be very handy against the Wallaby marauders and if he does not play, Senatore will play in the boot of the scrum. He is also a workaholic loosie without perhaps the cutting edge of his cronies.
Lobbe carries great mana among his team and has been captain of the Pumas before Agustin Creevy took over that role.
Lobbe plays No 8 or blindside and while his legs may have lost a little sting, his lineout work is a bonus and his general play has a charismatic edge about it.
He was one of the stars of the Pumas start in the Rugby Championship and a player who generally fronts in crunch matches.
Matera is the baby of the group at just 22 but he is also an assassin after forging a path at the 2013 junior world championships and making his test debut at 19.
Now he's in the big league and has also signed a three year deal to be part of the Pumas squad in next year's super rugby series.