Fifa World Cup: The test results are in and the Brazuca is more stable

With every World Cup, it seems, there is controversy about the ball. The Jabulani used in South Africa in 2010 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.

This week, scientists in Japan said the Brazuca, developed as the official ball for the 2014 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 six, the journal Scientific Reports said.

Balls traditionally are constructed from 32 panels. World Cup balls, which are re-designed every four years, lately have had fewer – Jabulani had eight 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 and trajectory.

The tests showed that Jabulani, dubbed “supernatural” by the Brazilian striker Luis Fabiano, did behave erratically, as several players suggested.

Brazuca, on the other hand, had the lowest drag of all the balls tested, followed closely by the traditional 32-panel sphere.

These two balls also had the most-stable trajectories.

Researchers concluded that because the total seam length on the Brazuca is 68 per cent longer than the Jabulani, it will add resistance that will allow the ball to fly more true at the speeds typically seen at the World Cup.

They found that the air resistance around the Brazuca, which at 437 grams is a gram lighter than the Jabulani, is minimised when the ball flies at around 20 metres per second, the approximate speed of fast passes in professional football games.

Simon Choppin, a sports engineer at Sheffield Hallam University in England, said the findings meant the Brazuca would be more predictable for the players. “It's much more likely to behave like the footballs they are used to playing with,” he said.

Choppin, who was not involved in the study, said the ball did not seem to have the problem of being too smooth, as some of its predecessors had been.

Smoother balls experience more drag and other “unsteady” aerodynamic forces while travelling through the air, whereas a rougher ball surface, created by panel seams, for example, caused the opposite behaviour, he said.

The seams on Brazuca, Choppin said, are deeper, thereby creating more surface roughness.

The research team said they have shown that a ball's characteristics can be used to predict its trajectory, which may be useful for coaching and planning.

And while predictability of a ball is good for long, running passes and goalkeepers, not everyone may be happy with Brazuca's steady-does-it features.

Some strikers prefer a ball to dip and swerve, as it helps them confound the keeper.

In other Wolrd Cup news...
Germany
Joachim Loew, the German coach, has played down concerns over the fitness of Philipp Lahm, the captain, and the goalkeeper Manuel Neuer.

Lahm is working his way back from an ankle injury and was seen grimacing after his participation in training on Friday was cut short.

“It was a precautionary measure,” Loew said. “He will rest this afternoon and do some more ball work on Saturday.”

Neuer, Lahm's Bayern Munich teammate, was on the practice field for the second day, but again protected his troublesome right shoulder.

Loew said: “He did a number of exercises. He still has a week of work and we're thinking he will be back in goal by Friday.”

Uruguay
Uruguayans hoping their team can pull off a repeat of their 1950 World Cup upset against Brazil have found a new source of optimism in a mathematical formula that has gone viral on social networks.

The magic number, according to the theory, is 3964. Brazil won the World Cup in 1970 and 1994; add them and the result is 3964.

Argentina won in 1978 and 1986, Brazil again in 1962 and 2002, Germany in 1974 and 1990. All add up to 3964. If the pattern holds, Uruguay should be due for its next championship this summer: 1950 plus 2014 is 3964.

Italy
Italy's coaches have tried to create a training environment in Florence to mimic the conditions the Azzurri will face in Brazil.

They have set up a small wooden shed beside their locker room, where players run on treadmills or ride stationary bikes in temperatures of up to 33°C and humidity of around 70 per cent.

The goal is to recreate the climate of northeast Brazil and the Amazon, where Italy play their three first-round matches.

England
David Beckham is facing an early start if he wants to watch England's World Cup opener against Italy on July 14.

The globe-trotting former England captain is in Singapore that day for a promotional event in far east Asia. With a 12-hour time difference from Manaus, Brazil, Beckham will have to be up at 6am if he wants to watch the game.