This is in order of importance to the teams' success, how the players in these positions can influence games during the knockout stages of the tournament.
8. France
This back three is undoubtedly the worst because of its inconsistency. I have no idea why they kept picking Yoann Huget. But if they play Damian Penaud, who is a massive star of the future, with Alivereti Raka and Maxime Médard at the back, they could cause some problems.
7. Australia
This is a difficult one. Marika Koroibete is class. Give him space and he will turn a game. Will they play Kurtley Beale or Dane Haylett-Petty at full-back? Does Reece Hodge come back in? Any back three that is not cemented should finish further down these rankings and the Wallabies are a prime example of that. As an Englishman, their backline does not fill me with fear.