Modern rugby, in short, is killing its playmakers. The glamour role of first-five is anything but. It is, probably, the toughest place on the field and not just because of the mental, strategic and technical demands that come with being the chief organiser. The problem is that athletes are being picked because of their skills and ability in that area and yet an equally big part of the job is defensive and abrasive.
Which player made the most tackles in the Rugby Championship? Kieran Read? Michael Hooper? Nope. It was Argentinian first-five Nicolas Sanchez. He made 69 - almost 12 a game and the majority would have been head on, bringing down men in excess of 110kg.
He's 1.78m and 83kg. After two years of that, just watch, pieces of him will start to break off.
That's what happened to Jonny Wilkinson. Defensively, he was outstanding - a crash-tackling phenomenon. But he paid the price. Between 2004 and 2007, he barely played. There was an 18-month period where he managed only 11 games, suffering a colossal range of injuries that included medial ligament damage, broken bones and a lacerated kidney.
The impact of taking the ball to the line inflicts an equally heavy toll.
At Twickenham, in the seconds before Carter was injured when he mopped up a loose pass and headed into the traffic, the English players could be hard yelling: "It's Carter, it's Carter ... smash him!"
It's almost impossible to have a body type that can excel at both the creative and physical demands: or rather, someone like Carter can, but for how long? The career longevity of a first-five is now questionable.
Cruden is the heir apparent yet, without being overly dramatic, it wouldn't be a surprise to see him incur the same scale of injury problems as Carter.
"Good question," he says with a smile straight after the England test in relation to how sore he'll be by the morning. "Normally pretty sore. It takes me a little while to get going. It can be pretty frustrating when you are only 24 years old. [At least] I have some downtime after Christmas to get the body right.
"It is a physical sport and gone are the days when 10s were sort of used as a quarterback, like in gridiron. A lot of teams are sending their big boys down that channel between nine and 10 so you know you are going to be pretty sore after the games but you come to accept that."
A combination of common sense and statistical analysis should lead every coach of the major nations to conclude they will need more than one genuine test quality first-five in their squad.
They are dreaming if they think one man can survive a whole season. Most of them are lucky to get through 80 minutes in one piece. In fact, the All Blacks have rarely even done that this season. Only three times in 2013 has the All Black No10 who started the game finished the game.
For one test - Australia in Wellington - New Zealand were down to their fourth and fifth choices; while that was extreme, it's commonplace for all major nations to come into big tests with their second and third choice options.
Ireland faced that problem this week and were genuinely either unsure about who would replace Sexton if he wasn't fit, or knew but didn't have any faith. That's why they waited until 48 hours before kick-off before making a final call on Sexton. The British Lion is significantly better than those underneath him.
It was noticeable, too, that when Farrell limped off against the All Blacks, England lost their way. Toby Flood didn't kick well and then gave away the penalty that put the All Blacks two scores ahead.
It's not like that with the All Blacks. Carter's injury dramas have not derailed the team or caused uncertainty.
Cruden has replaced him effortlessly. He's maybe not quite in the same league, but he's still a world-class player in his own right.
Just as significantly Beauden Barrett has probably provided some of the best moments of the season - his match-winning efforts against South Africa were outstanding.
Tom Taylor made an accomplished test debut in August to confirm that New Zealand have four No10s that are genuine test quality. They can weather the inevitable injuries and no longer have to wonder whether their entire game plan is going to fall apart because one man is not available.
"We are really happy with the way we have been able to deal with situations and it goes back a few years," says assistant coach Ian Foster. "Crudes played quite a few last year, we brought Beauden through in June last year so we are delighted with the way these guys have developed. Crudes has pretty much been on the open stage and had a pretty good role this year. Beauden has been simmering away behind the scenes and this year has been a real growth point for him.
"Then of course Tom Taylor came in and we are delighted we had him in the camps in May so that when he did have to start against Australia he was in a much stronger position. Having the guys around the environment is really useful. Sometimes it is hard to get that point across - but they see what it is all about."
In what has been a year of major positives for the All Blacks, perhaps the most significant has been the improvements made by Cruden, Barrett and to a lesser extent Taylor. New Zealand are now insured against the inevitable in a way no other side in the world game is.
