England (ranked 2nd) vs New Zealand (ranked 1st)
As far as rugby goes it doesn’t really get more exciting than this! The two highest ranked nations, both in form, facing off at a neutral venue, with a coveted place in the World Cup final going to the victor.
New Zealand and England started the tournament as the two highest ranked teams and have continued throughout in these positions. Both have extended their relative dominance in the rankings since the tournament began, adding to their individual ranking scores. Such progress was steady for both sides, the notable exception coming after New Zealand’s convincing win over Ireland in the Quarter Final. This resulted in their ranking score jumping to the significantly high level of 20.2
With a place in the final on the line, the stakes are huge. But importantly, this game represents the opportunity for England to replace New Zealand as Number One in the rankings. They just need to win the match by a high enough margin.
So, we all want to know – by what margin does England need to win to replace New Zealand at the top of the table for this World Cup?
And, in answer – as with all mathematical models, it is not straightforward!
It is not simply a case of beating New Zealand by a given number of points, since relative dominance of a victory is also relative to how free scoring the game is. For example, a score line of 7 – 0 is not considered to be the same as 37 – 30.
Due to the higher scoring opportunities in the latter example, it would be deemed a more ‘free scoring game’ and therefore more likely that the score line is due to chance. In this situation, the winning team is judged to be less dominant than the losing team and so they benefit less in terms of ranking score.
To demonstrate this visually, the score lines that will allow England to overtake New Zealand are highlighted with the lighter colour, (assuming no team scores higher than 30 points). All other score lines in this range are highlighted with the darker colour and suggest New Zealand would maintain their status as the number one ranked team.
Obviously, most of the graph shows the darker colour, so more possibilities for New Zealand to maintain pole position. This includes them losing by a range of margins. Conceptually, this does make sense as England have fewer ranking points, putting the onus on them to show a level of dominance over New Zealand to re-address this.
In numbers, to earn this accolade, some score lines that would work in England’s favour include:
- 7 – 0
- 13 – 3
- 17 – 5
- 30 – 13
And so on.
The performances of these two goliaths of International Rugby have set this up to be a titanic tussle for supremacy. With so much on the line, it certainly won’t disappoint!