Another factor could be that our hemisphere has much less industrialisation and hence, less pollution.
Then there's the puzzling way water drains clockwise in Northern Hemisphere countries. Maybe the Earth's gravitational pull has an insidious effect on northern players' balance.
I jest, of course, because the imaginary line called the Equator has been greatly exaggerated since the four semifinalists were decided. Let's not forget Wales lost by just four - and Scotland was robbed in a one-point defeat.
Given the two finalists, the real story is not the perceived chasm between hemispheres - but the sporting muscle of the Antipodes. The two southern colonies of Australia and New Zealand have made the final in the most recent incarnations of the netball, rugby league, cricket and now rugby union world cups.
Unlike the first three on that list, here's hoping the last piece of silverware will be heading the right side of the Tasman.