For a long time in Test match rugby, there was no such thing as a reserve, let alone a long bench of them.
A team turned up with 15 men and if a player got injured, he either gritted his teeth and played on or the team continued with 14 men. The odd heroic win was claimed.
In some periods of history, captains agreed between them to replace injured players but substitutions weren’t formally introduced until 1968, when the world agreed two players on a reserves bench was fair.
Neither could get on, mind you, unless there was a genuine injury, and that required a doctor to verify as much on the sideline.
Bench size grew over time. When the Wallabies won the 1991 World Cup, there were six players (three forwards, three backs) but the reserve winger wore 16 and the back-up hooker - David Nucifora - wore no.21.
With the scourge of fake injuries a growing concern, in 1996 tactical subs were first introduced by International Rugby Board.
And since then, the bench size has also steadily grown. It went to seven and then eight in 2016, to accomodate two props and ensure safe scrums could continue.
Forgotten are the not-so-distant days where reserves were deemed so irrelevant they often weren’t listed in the program.Now the subs bench is a critical element of success; so much so coaches increasingly hold a player back for their impact.
Like a baseball manager calling a pitcher from the bullpen, Michael Cheika began calling his reserves “finishers” in 2015 and that terminology has been adopted by many coaches, including Eddie Jones, around the world since.
Harlequins took it a step further this month by posting their team lists with the subs bench titled “Game Changers”.
It brings a wry smile but the new language actually reflects the modern game pretty well.
Time and again, games do indeed change when the reserves bench begins to enter the contest at around the 50-minute mark. To finish the game.
It is little wonder. When over half a team can be replaced by fresh legs and shoulders, games can and do dramatically change .
In post-game comments, coaches routinely point to the work of their bench as the reason for winning the game.
That’s also routinely debatable - without good work from starters a game can't be “finished” - but there is no argument that without a strong bench, a Test team will be pushing the proverbial up hill to get a win.
Which brings us to the opening Bledisloe Cup Test in Sydney on Saturday night, and a Rhino-sized conundrum that has emerged for Michael Cheika.
The rhino in question is Taniela Tupou, who is known as “Tongan Thor” by the outside world but goes by “baby rhino” inside the Wallabies.
Either name serves well to describe the giant Queensland youngster, who has shaken off his former viral fame and emerged as a genuine Test prop this year.
Tupou, 22, starred with his attack and defence for the Reds but more critically began using his 135kg to full effect in scrums as well.
He has improved so rapidly in this space he helped Australia win a vital scrum penalty late in the first Test against Ireland.
And when the Wallabies turned to live scrum training in the last month, it was the Tongan Thor show.
Tupou was so consistently chewing up rivals in recent camps, the question became: should the rhino be elevated from his bench spot and start in Bledisloe One?
The answer - as rolled out in Cheika’s team list - was no. He would remain a finisher.
But, as Wallabies assistant coach Mick Byrne explained, that’s no slight. In the modern age, it is actually a calculated call.
“The value that players give when they come off the bench is an enormous part of the team,” Byrne said.
“We look at NBA teams, they get rated by the strength of their bench over in America in basketball. Having players who can have that impact off the bench are vital to you and I think he (Tupou) is continuing to grow as a player, he’s certainly got more strings to his bow now.
“His scrummaging has improved, because he was that dynamic running player, his set piece game has improved enormously and he just keeps pushing the guys in front of him, which is a great place to be.”
Tupou is only young but he’ll scrum against a debutant All Blacks reserve loosehead Tim Perry, which helps.
Elsewhere on Cheika’s bench, the Wallabies can boast some impressive depth, and experience too.
Jack Maddocks is on debut but in Matt Toomua and Nick Phipps, the Wallabies get a combined 99 Test caps and two decades of experience.
Up front, Allan Alaalatoa has 22, Tolu Latu is in form, Rob Simmons has 85 caps and Pete Samu is new, but now a seasoned and successful pro too.
They can all fairly be labelled game changers.
The big question for the Wallabies - and Cheika’s call on a player like Tupou - is whether the game is still there to changed in the second half of Bledisloe One.
The last two years have seen the contest well and truly over by half-time, with New Zealand dominant. Down by more than 30 points, you could bring on the Avengers after the break and not “finish” with a win.
So it is some comfort for the purists that the “starters” - those poor forgotten souls who are deemed the best player in their spot - actually still matter. A whole lot.
For Tupou to make his mark, he must hope the old war horse Sekope Kepu first plays the house down in the no.3. Likewise, Tatafu Polota-Nau, Tom Robinson, Adam Coleman … the list goes on.
It is Captain Obvious territory but the Wallabies have only ever beaten the All Blacks in the last few decades when the scoreline is tight at halftime. They’ve even trailed and won.
But first they have to be in the game, up to their necks.
You can’t finish a fight you’re not in.