Smith hasn't so much transformed the way the All Blacks play, rather, he's been able to take them to a higher level with much the same philosophy they have had for he last decade of playing high tempo, ball-in-hand rugby that utilises the full width of the field.
He can't take all the credit, but his role in enabling the All Blacks to become a devastating final quarter team has been significant. The speed of their continuity is largely down to him - he's at every ruck, never late, and the second the ball is clear, his hands are on it, whisking it away.
There's no stutter steps, killing the space for others, as he winds up the pass. Three's no indecision or half-mindedness about his work and there is rarely inaccuracy. His pass is honed, crisp and of the few things in test football that could be called beautiful.
He played his first test like that and then 48 more, becoming, in what seemed like no time, part of the All Blacks fabric.
"I remember the first time I was named [in the squad] there was only two halfbacks me and Piri [Weepu] and I was thinking to myself that I might get 10 minutes in the first test and I was pretty happy," says Smith.
"And then bang, in the changing shed, I got named to start and oh my God it was actually happening. They just talk about do your job and I definitely feel that I got into knowing what I need to do for this team quickly.
"It is a very simple role for me - just to clear the ball as quick as I could and anything else I could was a bonus. So I have been trying to add communication, energy and that was how simple it was for me and that's how simple I think it is for me still to this day. I know that it effects my game when I try doing too much so Steve [Hansen] just says to me get there, clear the ball and do what you see.
"I think I'm at my best when I pass quickly and when the obvious comes I do it."
It's not solely the simplicity of his game that sets him apart - it's his ability to retain such clarity for such a prolonged period of time. Most international coaches are happy to get 60 good, high-paced minutes out of their respective No 9s. The All Blacks regularly get 70 out of Smith, if not more and if he has to, he can go the full 80 without the All Blacks losing that sweeping flow they are after.
That's what breaks so many teams - the relentless speed of the All Blacks attack game. It doesn't allow teams to breathe and as Wales have discovered this series, the All Blacks can suddenly go up a gear midway through the second half and hold it for 10 to 15 minutes.
Smith is typically at the vanguard of these deadly blasts. He drives the game harder and faster, makes himself the key decision-maker and biggest influence. And this is where reward outweighs risk - what he concedes in defensive muscularity, he gains in speed, aerobic longevity and high precision execution.
"I think in the earlier part of my career it was all about halfbacks having to be 90kg," he says. "They said they had to be able to take tackles and all this and it just wasn't my game.
"Dave Rennie was Manawatu coach and he said 'I like the way you play, you do need to get more accurate in the tackle but if you can play the way you play for 30 minutes but push that out to 70, 80 you will be able to go places'.
"So the big thing for me was getting aerobically and anaerobically fitter. Getting in there and making my tackles was important but what changed was the anaerobic game, being able to play the way I wanted. I could play for 30 minutes and then I couldn't play any longer at that speed.
"It changed when I changed up my fitness and I got really fit and I could be where I wanted to be for a constant time - maybe 65 to 70 minutes. I didn't used to like running but now I am a big fan of it."
He's reached the point where he's come to see those late periods in tests, when the oxygen debt is growing and players around him are gasping, as the moments in which he can define himself.
He doesn't know how long he'll be asked to play for tonight as with Tawera Kerr-Barlow having only just recovered from injury, the coaches may be keen to see the Chiefs man get some time.
But Smith won't worry about that or hold anything back - he'll just run and pass, as hard as he can, until he's told to stop.
"When it really hurts and when other people would give up, that is when I feel I have to work harder and that is when you find yourself the most," he says.
"Ireland in 2013 ... I remember thinking we have got to go 70 metres here but we had to. So we couldn't stop until we did it and I can remember Crotts [Ryan Crotty] scoring and I just dropped to the ground. Not because we had scored, but because I could rest.
"Pain is temporary but you remember those games where you didn't give up because I want to be an old man and look back and say that I went as hard as I could."
