Brazuca, the World Cup's ball of Brazil, is the most stable

Each year, the new version of the official ball of the World Cup cause a real stir. This year also expected with particular interest given the criticism it received the South Africa World Cup.

Traditionally, the balls used during this championship were not very different from the traditional: they consisted of 32 panels of hand-stitched leather. Since 2006, however, when Adidas introduced Teamgeist (composed only of 14 panels glued together rather than stitched), the company has been introducing new and different balls for the competition, as the Jabulani 2010 and Brazuca 2014.

Does it design change affect the game? Using wind tunnels and a robot, have shown that the resistance varies with the orientation of the panel and the friction is less the fewer panels  the ball have, an effect that is further enhanced by glue instead of sewing them. The brazuca also is more rugged, since this reduces the knuckling effect that is precisely what occurs when the ball becomes unpredictable and changes direction to reach a certain speed, which criticized the Jabulani. The Brazuca with its 6 most rugged panels seems more stable.

Still, as Choppin, a researcher at Sheffield Hallam University in Britain, says a wind tunnel is not comparable to a soccer field in Brazil. In his opinion, the effects observed by the team of Hong occurred in very controlled conditions in terms of temperature and humidity, which disappear once the players step on the field.