One of the things we learned from Rugby World Cup 2017 was that the World Rugby Women’s Rankings powered by Capgemini can take on a very different appearance from the tournament’s start to the tournament’s end.

That tournament was the first to be played after the women’s rankings were introduced in February 2016, and the end result had a pronounced effect on who sat where. Indeed, none of the teams in the top 10 stayed where they had been previously.

Eventual champions New Zealand replaced England as the world’s number one team following their victory in the final in Belfast, improving their rating score by 3.68 points.

Meanwhile, France moved into the top three at Canada’s expense and fellow semi-finalists USA climbed two places to fifth.

RWC 2017 featured play-offs for placings rather than a full quarter-final stage as is the case this time around, and Wales’ victory over Ireland during that now-defunct phase of the competition enabled them to finish three places better off in seventh.

What might happen this time around?

Lasting twice as long, Rugby World Cup 2021 will give plenty of opportunity for those teams who progress farthest in the competition to improve their rating score and potentially their position.

Rating points will be worth double what they normally are to reflect the prestige of the competition, which gets underway this weekend.

Other than the top three, England, New Zealand and Canada, who all play opponents significantly lower than them in the rankings, it is possible for all the remaining teams to improve their position this weekend.

While France are in a similar position in that they won’t get any additional points for a victory over South Africa, whose total is 17.59 points fewer, they will replace Canada in third if the North Americans lose or draw their fixture with Japan and they win.

Can teams break new ground?

Record highs are possible for Australia and Fiji if they cause the shock of all shocks and beat New Zealand and England, respectively.

If Australia can finally break their duck against the Black Ferns in emphatic style and other results go their way, third place is possible for the Wallaroos.

Meanwhile, a first-ever place in the top 20 would be more than a just reward for Fiji if they achieve what no other team has done in the last 25 matches and beat red-hot favourites England on their tournament debut. 

Defeat for England would not signal their reign at the top as, in the worst-case scenario, there would still be 1.21 points between themselves and New Zealand.

The Black Ferns could, however, drop as many as two places if they kick off their home tournament on the wrong foot and lose to trans-Tasman rivals Australia.

Significant milestones are possible for two other teams in that South Africa – the team that has gained the most rating points in the build-up to the tournament – and Japan could move into the top 10 for the first time.

The in-form Springbok Women take on France in their first fixture knowing that a victory will send them into previously uncharted territory.

Mind you, a Japan win against Canada might not be enough in its own right with the result of Wales v Scotland will also have some bearing on the outcome.

Wales’ game against Scotland will not only be pivotal in how the Pool A standings are likely to shape up by the end of October but also from a rankings perspective,

A win for Wales would send them up one place to eighth, while Scotland would become the higher-ranked of the two teams if they come out on top for only the third time against their Celtic cousins since 2006.

With Italy and USA currently positioned at fifth and sixth, the outcome of their match also has the capacity to affect the rankings.

USA will climb one place to fifth at Italy’s expense if they win their Pool B encounter, while Azzurre need to win by a big enough margin and hope Canada and France fare spectacularly badly in their first run-out in New Zealand.