Adidas designs every World Cup ball, and on top of being a big seller for them, engineers at the company are constantly a little closer to the perfect ball, Goff says. The ideal soccer ball is a pimple-covered, perfect sphere, its surface just subtly textured enough to keep the airflow around the ball slightly turbulent. Unintuitive as this might sound, the ridges and pimples on the ball make it more aerodynamic, helping the ball to fly through the air more stably.
A radically new configuration reduced the amount of panel touch points forming a smooth and perfectly round exterior that improved accuracy and control. Prior to the Teamgeist, the surface of World Cup match balls had notable differences depending on where a player would strike the ball due to seams, ridges and other imperfections where panels come together. The revolutionary propeller design of the Teamgeist minimized corners and created a smoother surface for improved play. The ball was designed with traditional colors of the German flag and was accentuated with the golden color of the World Cup trophy. 
On the other hand, replicas (sometimes called training balls or gliders) are designed to be just like the official match balls but are much cheaper. Their panels are often stitched rather than thermally-bonded and are made of a different material. However, they’re not necessarily less durable than official match balls. So, they’re the recommended option for most players. https://www.youtube.com/watch?v=j2Xn84L3Kcs
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