[math-fun] Soccer balls

Not being a big soccer fan, not across the latest on the design, authorised use and reasons for the shape and construction of soccer balls. Looking at the opening game I noticed the truncated icosahedron ball is no longer in use. I found this article which compares the properties of different shaped balls http://www.nature.com/srep/2014/140529/srep05068/full/srep05068.html Does anyone know why the truncated icosahedron is no longer used in the World Cup? Sent from my iPhone