By James Rodbourn
As we get set to embark on the Super Rugby Aotearoa competition, a lot of talk has been around the supposed fiercely competitive nature of New Zealand Super Rugby ‘derbies’. But is this actually the case?
The below table shows that over the course of Super Rugby history, the average winning margin in a NZ derby is 2.3 points less than in all other Super Rugby matches. Given that this is a sample size of over 2000 matches, this is not an insignificant difference. This difference is even more pronounced in the last 5 years, with the NZ derbies maintaining their relative closeness while the struggles of teams like the Reds, Kings and especially the Sunwolves blow out the ‘non NZ derby’ average winning margin to 15.8, 4.4 points more than an all-NZ affair in that time period.
Another measure of competitiveness might be how unpredictable the games are. According to bookmakers’ odds since 2009, NZ derbies have more upsets than other Super Rugby matches, with favourites winning 5% less often and underdogs winning 32.4% of the time, compared to 28.2% of the time in all other games.
The third and fourth rows above show that the number of upsets has actually decreased not only overall in the last 5 years (again see Kings, Sunwolves etc) but in the NZ derby games as well, with the upset percentage dropping closer to the competition average at 27.9%. This can be explained almost exclusively by the recent struggles of the Blues, who have won just 4 of their 39 NZ derbies since 2015 (unsurprisingly having started most of those games as underdogs). The table below shows how much of an exception the Blues have been:
Just for fun, if we take the Blues games out of the equation for the table below, we see that in NZ derbies the favourites won roughly 9% less often in the last 5 years than in other Super Rugby games, with underdogs winning an impressive (and more exciting for the neutral viewer) 33.8% of matches.
And with the Blues shaping up as being much better in Super Rugby Aotearoa than in recent years, we might just be heading for plenty more upsets and close games.
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