The starting forwards are expected to play 40 minutes plus 10 minutes (or so)
During that time, they are involved in various tasks, most of them being heavily energy consuming.
Forwards must manage themselves over the period of time. It is a matter of balance to avoid overspending oneself.
SA rugby applies attrition to the game.
They relieve their forwards from many tasks usually allocated to forwards. This ensures they save energy compared to other forwards.
The other part is SA rugby efforts are applied to making the opponents' efforts costier.
This is not a defensive attitude by the way. It is about ruining the opponent.
This approach only works when the other team is committed to spend themselves in playing rugby.
And from this point, it was over. SA rugby could no longer hope their opponent would tire themselves trying to play rugby. They had to react which they did by gambling early substitutions.
This point is key as shown by the last game: NZ refused to play rugby and then, attrition could no longer be applied.
