There may be an answer to the vexing problem of Damian McKenzie's exit from this year's All Black World Cup squad, one we've all overlooked – Jordie Barrett.
McKenzie's injury strikes a lot deeper than 'who will be the third first-five?' The absence of the little Chiefs flyer upsets the whole balance of the backs division of the 31-man squad and reduces the All Blacks' X-factor.
These selectors have preferred a 17/14 split forwards/backs. To achieve that and cover injury and form eventualities, they need utility players. McKenzie is more than that – he fits snugly into the All Blacks' two-playmakers plan and his injection from the bench can create match-winning havoc in those last 20-30 minutes.
If the selectors plump for a third specialist first-five, that player will have, at best, minimal game time and, at worst, none. Plans of taking three halfbacks, two first-fives, four midfielders and five wingers and fullbacks (the latter including McKenzie) would have to be amended.
If a third first-five comes in, a player must make way from elsewhere, most likely the midfield or outside backs. The All Blacks won't take only two halfbacks. They could sacrifice a third hooker to make it a 16/15 split or drop a loose forward but those options seem extremely unlikely.
The World Cup will be dominated by two facets at the business end of the tournament – kicking and ironclad defence. The northern hemisphere sides which did well against the All Blacks (England, Ireland and let's not forget the Boks beat the All Blacks last year) have used those key tools and will do so again.
Whoever replaces McKenzie not only needs utility value, able to play first-five and fullback, they need to have good kick-receiving and counter-attacking skills.
That's where Jordie Barrett comes in. In terms of utility value, let's not forget he first starred for the New Zealand under-20s at second-five. He can play there, centre, wing (four tries in one test against Italy), fullback and, when he was starting out down in Canterbury, he filled in on occasion at first-five.
He also has that cannonball goalkicking from distance – a very handy weapon at World Cup time – and restores a bit of X-factor. He has nine All Black tests behind him.
It may sound a bit unusual – a 1.96m (6ft 5ins) first five close to 100kg – but Barrett would be an injury backstop at first five, ideal for the bench role.
One issue is game time at 10 for him to gain confidence. The All Blacks' Buenos Aires test against Argentina on July 21 is one opportunity as is their last warm-up test against Tonga in September. In between are a test against South Africa and home-and-away fixtures against Australia – perhaps time for some Barrett action off the bench if they want to keep to their dual playmaker plans.
So who else might make the trip to Japan in the midfield and outside backs if Barrett is included?
That could rule out veterans Ma'a Nonu and the very unlucky Ryan Crotty. If Sonny Bill Williams is injury-free, he seems a certainty, as is the fluid and efficient Jack Goodhue at centre. Ngani Laumape has the ram-raider, smash-and-grab potential to back Williams up at 12 and the fourth place could be fought out by Crotty (predominantly but not exclusively a 12), the very-much-in-form Anton Lienart-Brown (predominantly but not exclusively a 13) and Nonu (who can also play both).
Crotty and his concussion issues make him an injury risk and, with only four midfield spots likely, Lienart-Brown may be preferred for his bench role and X-factor late in a test.
The outside backs could be: Ben Smith, Rieko Ioane, George Bridge, Jordie Barrett with one spot left, maybe for a specialist winger (Smith, Bridge and Barrett can all cover fullback, as can Beauden Barrett, if necessary). So the final spot could go to Waisake Naholo or Ben Lam, who would be in just about every other country's World Cup team.
If he returns to fitness and form, Naholo is probably the man and also provides some X-factor, another big selection consideration for the All Blacks. Remember the effect Nehe Milner-Skudder had on the 2015 World Cup? Now both he and McKenzie are gone and, in a rugby world dominated by defence, McKenzie's speedy scampering and space-making runs will be sorely missed.
The only current All Blacks with some X-factor are Beauden Barrett, SBW (if fit), Ardie Savea and, arguably, Lienart-Brown. That may strengthen the appeal of uncapped No. 8 Akira Ioane, for all his previous work rate and discipline problems; a forward who can pierce defences like he can may be crucial.
No one is pretending Jordie Barrett is a like-for-like replacement for McKenzie but at least he has that "what next?" unpredictability about his play that can make things happen.
There are other possibilities – starting Richie Mo'unga at 10 and Beauden Barrett at 15 with Jordie Barrett to come on later but, now McKenzie has gone, most think the world's best fullback, Ben Smith, should start there.
So that's how Damian McKenzie's absence reaches much further into the All Blacks' potential squad formation than just deciding who the third first-five might be.
Seeing how the selectors fill that gap and top up the X-factor will be intriguing.