With every World Cup, it seems, there is controversy about the ball -— the Jabulani used in South Africa was said to be so unpredictable as to border on the "supernatural."

The Fevernova used in South Korea and Japan in 2002 was said to be too light and bouncy, while some complained that Teamgeist used in Germany four years later was slippery.

On Thursday, scientists in Japan said the Brazuca which adidas developed as the official ball for the World Cup in Brazil, should hit the mark.

It had a stable flight trajectory thanks to its shape and number of panels -— a record-low 6, they wrote in the Nature journal Scientific Reports.

Traditionally constructed from 32 panels, more recently the ball that is re-designed every four years for the sporting world's greatest spectacle, had fewer — Jabulani had 8 panels and Teamgeist 14.

A pair of engineers at Japan's University of Tsukuba compared the aerodynamics of the Brazuca, Jabulani, Teamgeist, the Cafusa used in the 2013 Fifa Confederations Cup, and the conventional 32-panel ball in the laboratory.

They used wind tunnel tests and kicks with robot legs to measure drag, also called air resistance, and trajectory.

The tests showed that Jabulani, dubbed "supernatural" by Brazilian striker Luis Fabian, had, indeed, been an erratic ball. Brazuca, on the other hand, had the lowest drag of all the balls tested, followed closely by the traditional 32-panel sphere.