Copyright: Picture-Alliance/ASA Goalkeepers are not too keen on the World Cup ball - perhaps because its smooth surface doesn't allow for a firm grip.

This explains why goalkeepers are not too keen on it, as a rougher ball would be more stable and allow for a firmer grip. But more seams and panels also create a disadvantage since they make the surface less uniform, affecting the ball's behaviour depending on the exact part of the ball the player makes contact with. The Adidas Teamgeist underwent extensive testing at the University of Loughborough and they found that its performance was extremely precise and consistent each time it was kicked straight on - allowing the players' skills to shine through without interference from the ball.

But James also mentions that the precise behaviour of moving spheres is still elusive to scientists and is something that sports researchers are just starting to look at. The University of Sheffield, for example, is using computational fluid dynamics (CFD) to create models of how air moves around a soccer ball - and their results could influence future ball designs.

Copyright: University of Sheffield and Fluent Europe Ltd Researchers at the University of Sheffield modelled how air behaves as it moves around a soccer ball.

In future World Cup tournaments, we may also see technology embedded in the official ball. Placing a sensor in soccer balls has been suggested as a way of monitoring the position of the ball in space and precisely measuring if it is 'in' or 'out'. Some people think this is not necessary and will take away from the spontaneity of the sport, but players are sure to have their own opinions as well since it will change the texture of soccer balls. The sensor would have to be placed exactly in the center of the ball and will have to be embedded in foam for it to stay in place. I guess we'll have to wait and see if it will favour midfielders or goalkeepers...

For more info:

Soccer Ball World - Official World Cup Teamgeist Soccer Ball
http://www.soccerballworld.com/Teamgeist.htm

University of Sheffield - Sports Engineering Research Group
http://www.shef.ac.uk/mecheng/sports/html/index.html