After more than thirty years of making soccer balls for the World Cup, in 2006 Adidas started mixing things up. That year, the standard 32 stitched panels were abandoned for a radical 14-panel design. In 2010, the number of panels shrunk down to eight. This year, the ball has only six panels.
Every time the design has changed, it's caused confusion and complaints from players that the ball moves differently—in unexpected ways—through the air. How will this new ball fly?
On the technical side, there's a clear answer to that question: scientist Simon Choppin has undertaken a detailed analysis of the ball’s aerodynamics. You can read his full walk-through at The Conversation. But the short version is: this ball has far shorter seams than its predecessors. Seams impact the airflow over the ball, Choppin explains:
As air flows over a smooth, sleek object, it hugs the surface until it has passed over it completely, creating very little drag. Air flowing over a ball behaves differently, it separates from the surface, creating an area of low pressure behind it – a wake. The low pressure region creates drag force and slows the ball. At low speeds, the air flow is smooth (laminar) and separates early, creating a large wake and relatively high drag force. As speed increases the air becomes more chaotic (turbulent) which helps it stick to the ball for longer, reducing the size of the wake and lowering drag force.
In the 2010 World Cup, players complained most about swerving balls: any little gust of wind or change in the air could make the ball turn and move. But this year’s ball might not have that problem, Choppin says. The seams in this new ball are deeper, he says, which will create more drag and steady the ball in the air.
On the subjective side, it's almost guaranteed that players and coaches won't be entirely happy—they never are. Choppin's final analysis: “While players and coaches may well find something to complain about with the Brazuca, it is certainly not a beach ball.”