Sean Fitzpatrick believes the strength in depth of the southern hemisphere's big guns is a major factor in their Rugby World Cup dominance.
No northern hemisphere side progressed past the quarter-finals for the first time in World Cup history, with the Rugby Championship quartet of Argentina, Australia, New Zealand and South Africa set to do battle for the Webb Ellis Cup.
Wales suffered a plethora of injuries in their backline and fell to a last-gasp defeat to South Africa, while Ireland lost five first-teamers heading into the knockout stages and shipped over 40 points against Argentina.
"We said right at the start of the tournament that the attrition on players would be huge," said Fitzpatrick, a World Cup winner with New Zealand in 1987.
"The games have been very close and could have gone either way. Australia could have been knocked out by Scotland. We've seen an Irish team and the effect losing Johnny Sexton and Paul O'Connell had on them.
"Probably the big difference is the depth of the squads, and obviously a little bit of skill level and being able to close out games.
"The real tell-tale factor is when you lose that key experience, hence why we've seen New Zealand, South Africa, Australia and, to a degree, Argentina being able to cover positions when they lose players."
Benefits
New Zealand's 49-point annihilation of France was the standout performance of the quarter-final stages but Fitzpatrick was also impressed by Argentina, who produced a superb attacking display to beat back-to-back Six Nations champions Ireland.
"Traditionally, Argentina have performed really well at World Cups," he said. "In 2007 they finished third but I think we're really seeing the benefits of them playing in the Rugby Championship for the last few years.
"Playing against three of the best teams in the world, you're only going to get better. To beat South Africa in Durban this year was a real milestone and they've taken that form into the World Cup.
"If you look back to day three when Argentina played New Zealand at Wembley, for 60 minutes they had the All Blacks under a lot of pressure. We said after that game that whoever plays Argentina in the quarter-finals had better watch out.
"After the All Blacks game they had a pretty easy run through to the last-eight. They went under the radar, they were fresh and they blew Ireland out of the water in the first 20 minutes."
'Four best teams in world rugby'
Argentina are underdogs against an Australia side that scraped past Scotland last weekend, and Fitzpatrick is predicting a first ever World Cup final meeting between holders New Zealand and the Wallabies.
"We're definitely got the four best teams in world rugby at the moment in the semi-finals. It could go any way, we've seen that in the competition," he said.
"I think New Zealand have timed their run pretty well; they're the best prepared All Blacks team I've seen.
"In the pool games they were making about 25 errors per game; against France they made six mistakes. Teams cannot live with the All Blacks if they do that.
"They will try to replicate that against South Africa, which will be difficult as the loss to Japan was a blessing in disguise for the Springboks. They've got a real blend of experience and physicality in that forward pack, and Jesse Kriel and Damian de Allende have been outstanding in the backs.
"Argentina upset Ireland and could possibly do the same against Australia, but the Wallabies had a massive wake-up call against Scotland and David Pocock coming back in will make a big difference.
"I think the All Blacks will beat South Africa and play Australia in the final."