Probably because Richie McCaw was locked into the jersey for so long it prevented everyone in New Zealand from realising how much the role of an openside was changing at international level.

But now that he's retired, the requirements and demands suddenly look different. The full extent of what it takes to play test football at No 7 is starting to become clear.

And the first thing that has become apparent is that size and weight are now considerably higher up the selection criteria than they were.

At 1.88m and 106kg, McCaw was not a strikingly large athlete. His game was built around his timing, endurance and instincts and while he was strong and powerful, these were never considered the defining characteristics of his game.


The same would be true of New Zealand's other great openside, Michael Jones. He played in a different era of course, one where all the players were comparatively smaller and less powerful, but again, his key attributes were speed, awareness and refined ball skills.

These two brilliant players were supremely conditioned, lean athletes who were obviously not as heavy or as similarly dimensioned as the men with whom they played alongside in the loose forwards.

This week, however, size and weight has been the prevalent theme with both Ardie Savea and Sam Cane. The former, who starts on the bench at Soldier Field, is on a programme to get heavier. He sits around 103kg and the coaches want him to be closer to 106kg-108kg.

Cane has made that jump already, and from being around 100kg in his late teens, he's now at 109kg and that extra size he has added, is being given ample credit for the way he has played this year.

"Even in the last three or four years the physical requirements on a seven have changed," says Cane. "I reckon five years ago 100kg-103kg that was good enough. But we are seeing guys who are five or six kilos heavier than that now running around at openside so that is just the physical demands of the game.

"I was probably about 103kg when I first came into the team and I sit between 108kg and 109kg now. It is a wee bit packed on. I probably lost a bit of baby fat in that time too but a lot of it for me has been learning about nutrition and a lot more training years in the gym.

"I think you notice that it is not quite as easy to get around the field so you have to work hard on that aspect but you certainly notice in it in the collisions."

And it's that ability of Cane's to make his presence felt in the collisions that separates him from Savea and Matt Todd, the other openside in the All Blacks tour squad.

It's not that Todd and Savea can't win turnovers, make tackles or carry the ball, it's just that Cane can do it more effectively as he has more size and power. That's largely what sets him apart at the moment.

"I think what the weight does with Sam is allow him to do the stuff that Matt [Todd] does well which is to get over the ball and pinch it. But to also have a real presence defensively and with the carry.

"It is the old adage ...the big strong guy who can do everything that the little guy can do has got the advantage because he's got size. Our game is combative and is becoming more so but you can't lose sight of what the core role of that position is and Sam has been able to put size on and keep those skills."

The extent to which size matters is best put into perspective by looking at the enormity of some of the players in the current world game. Sam Whitelock came into the All Blacks in 2010 at 108kg and is now 122kg. Patrick Tuipulotu is 127kg and Charlie Faumuina is 133kg.

These are typical weights of international locks and props and an openside who sits around 100kg is having to compete physically with men who are often 20kg-35kg heavier.

That size differential - even between Cane and some of the bigger tight forwards - is also partly responsible for evolving openside into a dual role.

Cane could no doubt go the full 80 minutes if asked but the prevailing view is that the demands are so extreme that it is probable that he'll lose some of his impact later in the game. It has reached the point where it is not realistic to expect a starting test openside to be able to go much beyond 65 minutes without fatigue biting into their contribution.

"I think traditionally as a seven you pride yourself on your fitness and your ability to go 80 minutes," says Cane. "The way it has changed his year and the player that Ardie is, too, he has been able to bring a lot of impact off the bench in the last 20 minutes-30 minutes.

"So whatever works best for this team. You know that is always the case and that is drilled into us all the time and the guys firmly believe it too that whatever the selections are it is not personal, it's not because one guy is better than the other. It is what is best for the team and to help us get the best results and that seems to be with a two punch combo at No 7 this year."