Aaron Smith's quest to make an unprecedented third World Cup as the starting halfback

Halfbacks rarely make it to two World Cups in New Zealand, let alone three as the starting No 9.

Byron Kelleher did make it to three campaigns as his 12-year international career was bookended by World Cup years, but he was really only the starter for his last effort.

At the 1999 World Cup, Justin Marshall started the tournament as the number one option, taking over from Graeme Bachop, who had started in the final four years earlier in South Africa.

Kelleher, Marshall's deputy through the early stages of the World Cup, surprisingly took the starting job against France in their ill-fated semi-final loss which saw the All Blacks famously dumped out.

Four years later, Marshall had resumed the starting role again and Kelleher was the backup in the semi-final defeat to the Wallabies.

By 2007, it was Kelleher's time to be the number one starter, with Brendon Leonard and Andy Ellis acting as back-ups.

The 2011 World Cup-winning side featured a trio of Piri Weepu, Jimmy Cowan and Ellis, none of whom lasted to see the Webb Ellis Cup lifted for second consecutive time by the All Blacks in 2015.

Instead, Aaron Smith, who will go down as New Zealand's greatest ever halfback when he hangs up the boots, announced himself as an All Blacks starter in 2012.

Smith's era as the All Blacks' No 9 has been long and glorious. He has won the Bledisloe Cup every year since his test debut, has been part of eight Rugby Championship-winning squads and was key in New Zealand's 2015 World Cup success.

He has won 87 percent of his 101 tests, 93 of which he has started, forming an ever-reliable one-two partnership with TJ Perenara that has spanned two World Cup campaigns.

However, the big question stands as to whether Smith is the best option for the All Blacks as their starting halfback for a third World Cup in France next year. The first reaction from most will be of course he is, it is Aaron Smith.

But this is historically uncharted waters. Smith will turn 34 this November and will be 35-years-old a month after next year's tournament finishes.

Can he still play? Absolutely he can, but would his inclusion as New Zealand's chief halfback be the best selection to win the World Cup? How many other tier one teams will be using a halfback nearly 35-years-old?

All Blacks boss Ian Foster and his fellow selectors could be sentimental about it, keep the faith and keep Smith in the job based on his storied and glittering career.

He would undoubtedly give his best effort, which is still a very high standard, but it can not be said that he is at his peak athletically.

That much is obvious. In terms of speed, elusiveness, and defensive capability, prime time Aaron Smith was a few years ago.

If he is still the first-choice All Blacks halfback at next year's Cup, Smith will have to outplay 26-year-old Antoine Dupont in tournament opener.

He would then have to face either Faf de Klerk, who will turn 32 during the World Cup, or 31-year-old Jamison Gibson-Park in a quarter-final.

It seems like a lot to ask for a soon-to-be 35-year-old as those players will have the edge on Smith in terms of physical traits and stamina around the field.

The other halfback options that have been used under Foster are Perenara, Brad Weber and Finlay Christie, who - at the respective ages of 32, 31 and 27 next year - are all on the older side.

The young uncapped options are 21-year-old Cortez Ratima and 22-year-old Folau Fakatava, who still needs a World Rugby exemption to be selected by New Zealand.

Both of those young halfbacks are more explosive athletically and will be even better a year from now, while the others will all be a little older, a little slower, and a little less accurate with the pass.

To that extent, either Ratima and Fakatava should be fast-tracked into the All Blacks as soon as possible, at least to see how they take to international rugby and build experience to give the side a younger option.

The case with Smith is similar in multiple other positions where experienced veterans are holding onto starting roles.

It is true that the depth in New Zealand Rugby is not what it used to be, due to myriad of factors, which is why NZR has tried to extend the careers of a few experienced legends that, in years gone by, would have already been replaced.

The famous quote "hard times create strong men, strong men create good times, good times create weak men, and weak men create hard times" springs to mind when looking at the dilemma the All Blacks are now in. This saying isn't about the players, rather the men tasked with making decisions.

The good times of back-to-back World Cup wins has softened the decision makers to some degree within New Zealand Rugby and the All Blacks, who used to rejuvenate the team all the time and players were forced to give up the jersey sometimes earlier than probably needed.

Has Foster had to really make any tough calls yet? This is still largely Hansen's '19 side with the pieces moved around or tried in new positions, with only Kieran Read missing due to retirement from the international game.

The loss in 2019 should have been the end of that era and a chance to restart, but they handed Foster, Sir Steve Hansen's assistant, the head coaching role to keep continuity.

He then got a contract extension that will keep him in that role until the 2023 World Cup. That decision was rubber-stamped by New Zealand Rugby before any crucial tests - most of which the All Blacks lost - were played last year.

As such, Foster must now decide between making bold calls or weak and easy selections in key positions as the side looks to build into the France campaign, like at halfback where the stocks are getting older.

The public is not going to hang Foster for sticking with Smith, an all-time great of game. That is the point. The toughest calls are never easy, but they are sometimes required to get somewhere.

Does he stick with Smith all the way through to next year's World Cup, or does he take a chance on a player like Ratima now and see what youthful athleticism, which Smith once brought to the All Blacks, can do for the team? Maybe there is still room for both at this stage.

It's not just Smith either, there are others. But on Smith, he has done everything in the game and set the bar at a level that may not be reached by another halfback in New Zealand for a very, very long time. He is the best the country has seen, that will not change regardless of what happens now.

This purely about what is going to happen in 18 months time if the All Blacks rock up with largely the same team that didn't win in 2019, who will all be four years older, and have been shipping losses to key opponents regularly.

The big difference between the group in 2015 that did win with experienced players like Kaino, McCaw and Carter is at no stage during the cycle did the All Blacks ever stop winning. That is not the case now.

Maybe Foster doesn't know where this All Blacks team is going yet, but there is a feeling of resignation among the rest of us about where they are headed should change not be underway against Ireland in a couple months time.