soccer ball technology

Adidas's FIFA World Cup history, 1970-2014Thought I ought to know something about soccer ball technology, given that the hexagon ball which has held sway for decades appears to have been replaced by something much more free-form and sinuous.  

The first World Cup was held in 1930, in Uruguay. The ball had twelve panels, leather, two of which were laced to tighten the outer shell over the inner ball, originally in the 19th century an inflated animal bladder, later rubber.  The quality of the ball had much to do with the quality of the leather, and whether it came from the rump (good) or shoulder (less good).  The six panels of two strips became six panels of three strips each, making the ball smoother, then changed back again.  There were other variations: interlocking T-shapes, other geometries.  It is a parallel investigation to map-making where a round globe is represented by flat paper; here flat pieces of material are shaped and stitched together to make a globe.

Adidas's twelve panel white leather football for the 1966 World Cup1970 Adidas Telstar football, Buckminster Fuller's truncated icosahedron sphereBuckminster Fuller designed an infinitely smoother ball in 1970 of twelve pentagons and twenty hexagons composed as a truncated icosahedral sphere. Hexagons and the pentagons at their intersection were coloured black and white for television visibility and, supposedly, for the players to more easily see how the ball was spinning. Up to this point all footballs had been single colours.  The Bucky-ball, as it is known but called by Adidas Telstar, was used in FIFA World Cup matches until 2006 when a fourteen panel ball was introduced, in 2010 the eight panel Jabulani ball was developed.  

The eight panel Jabulani is made of thermally bonded moulded panels of ethylene-vinyl acetate and thermoplastic polyurethanes, textured with specific grooves designed to improve aerodynamics. Evidently players don't actually like this ball; it changes direction in mid-air and performs completely differently in different altitudes.  Curious that such a high-tech construction and aerodynamic design makes such an unpredictable ball.  One does wonder what influenced its adoption.  Adidas-sponsored players claim to like the Jabulani. 

From a NASA study mentioned on wikipedia: When a relatively smooth ball with seams flies through the air without much spin, the air close to the surface is affected by the seams, producing an asymmetric flow. This asymmetry creates side forces that can suddenly push the ball in one direction and cause volatile swerves and swoops and this effect is referred to as knuckling. Older designs of the ball have a knuckle speed of around 30 miles per hour (48 km/h).... the Jabulani, with its relatively smoother surface, starts to knuckle at a higher speed of 45–50 mph (72–80 km/h). This coincides with the typical speed of a ball following a free-kick around the goal area making the effect more visible.

There have been subsequent developments, the current ball being used in Brazil is called the Brazuca, eight panel, very decorative.  Smooth balls with little obvious construction or material markings offer a good surface for graphics so that the most recent balls are like small demonstrations of national identity.  Brazil's World Cup ball is all coloured ribbons, very curvy, like the pavements at Ipanema.
Here is a video comparing the official Brazuca with a replica.  The real one is covered all over with little bumps: this will be the aerodynamic stuff.  The replica is shiny as a billiard ball.

Football technology is a huge area, the images will take you to a couple of comprehensive sites with lots of information on the history of soccer balls. It's all very interesting.