An Australian columnist says the All Blacks dominance threatens world rugby.
Writing in the Guardian, Bret Harris says the success of the All Blacks might be wonderful for New Zealand, but questions remain whether it is positive for test rugby and the health of the game in other countries.
"This is particularly true for Australia, as the Wallabies play the Kiwis more often than any other team," wrote Harris.
"Never in the history of sport has there been an international team as dominant as the All Blacks. The New Zealanders have lost only two games since winning the 2015 World Cup - an exhibition against Ireland in Chicago and the second test against the combined might of the Lions, which they played with 14 men for almost three quarters of the game after Sonny Bill Williams was red-carded.
"While New Zealand has been the top country in world rugby for more than 100 years, the All Blacks have not always been invincible, especially at the World Cup from 1991 to 2007 when they were regularly knocked out in the play-off stages.
"The All Blacks would dominate test rugby in between World Cups only to choke at the showpiece event, giving the likes of Australia, England and South Africa an opportunity to claim the mantle as the world's best team.
"But the All Blacks have now won the last two World Cups in 2011 and 2015 and it is not beyond the realms of possibility they will remain undefeated until they lift the Webb Ellis Cup again in Japan in 2019.
"This kind of dominance is abhorred in other sports. Most professional sporting competitions have introduced drafts and/or salary caps to maintain parity among teams, seeing it as detrimental for one side to win all the time, but these sort of equalising mechanisms are not applicable to test rugby."
Harris said England was one side which could threaten the All Blacks.
"Under former Wallabies coach Eddie Jones, England are certainly mobilising their forces to make a genuine assault on the World Cup in Japan, instilling the same will to win that the men in white had in 2003. Rugby supporters around the globe are salivating at the prospect of England hosting the All Blacks at Twickenham in November next year, but that is a long time to wait to see the Kiwis knocked off their pedestal.
"In the meantime, the Wallabies and the Springboks look as if they have turned the corner, raising hope that a famous win against the All Blacks is not too far away. Both Australia and South Africa gave the All Blacks a run for their money in the Rugby Championship, narrowly losing epic contests in Dunedin and Cape Town respectively.
'['France, of course, are always a wildcard at the World Cup, having knocked the All Blacks out of the tournament in 1999 and 2007 and almost upsetting them in the final in Auckland in 2011. The All Blacks play France in Paris on their end of year tour. Les Bleus always step up when they play New Zealand and will be a formidable opponent."
There was a danger though, according to Harris that the All Blacks could turn rugby into "a big yawn".