Extensive Tests On The New World Cup Soccer Ball Tell Us What Strengths Will Help A Team Win
Sports science researchers from the University of Tsukuba in Japan put Adidas's new Brazuca ball, unveiled in December of 2013, through an intense series of tests. They compared it to a traditional ball, as well as the balls used in the Champions League, Confederations Cup, and previous World Cups.
In their testing they utilized not only a wind tunnel but also a kicking robot, seen below:
Not the first ball uproar
The new World Cup Brazuca ball has only 6 panels, compared to the normal 32. The panel number on a game ball has been controversial in the past. The decision to use a smooth, 8-paneled ball called the Jabulani at South Africa's 2010 Cup created a huge uproar when announced.
"It is very sad that a competition so important as the world championship will be played with such a horrible ball," said Italian goalkeeper Gianluigi Buffon.
Keepers particularly disliked that ball, and claimed it had a tendency to unpredictably swerve at the last minute, though strikers found that effect less disturbing. Brazil's Luis Fabiano called it "supernatural."
While the players had their fun complaining, it doesn't seem to have impacted the actual results of the games - the number of goals scored in individual games wasn't particularly high or low.
NASA testing even confirmed the Jabulani's "knuckleball" effect. They noted that the elevation some of the games were played at could have worsened the effect (Johannesburg is at 5,500 feet).
There was also an uproar during Germany's 2006 World Cup, which used a 14-panel Teamgeist ball.
Why does the number of panels matter in the first place?
With fewer panels, the 2010 and 2006 balls had smoother, rounder surfaces in general. Those rounder surfaces meant that at high speeds, air could push against a seam on the surface and send the ball in an unpredictable direction. The dimpled surface on a golf ball makes it fly through the air much more smoothly than a perfectly round ball could.
This would seem to imply that this new 6-panel ball could be even more erratic.
Not so, says study author Sungchan Hong. His research with the ball shows that, other conditions being equal, the Brazuca should generally be at least as consistent as a "normal" 32-panel ball.
The Brazuca has deeper seams that cover more of the surface than those from the ball used in South Africa, which may help correct its flight pattern.
Hong told Business Insider in an email that the ball's aerodynamics make it the fastest of all those tested at intermediate speeds, which could be "advantageous to the team using the pass like Tiki Taka," which is a name for the fast-passing Spanish style of play.
While all balls move as they fly through the air - and players add their own spin to the ball - this latest study confirmed that the ball used in South Africa was more unpredictable than the others, and that the one used in Brazil should be more consistent.
What other tests reveal
Other tests showed that changing the orientation of the ball before it was kicked made less of a difference with the Brazuca than with most other balls tested, as seen in the chart below.
Simon Choppin of the Centre of Sports Engineering Research at Sheffield Hallam University has also examined the ball, and expects fewer complaints - about the ball's flight, at least, though as he points out, "players and coaches may well find something to complain about."