Coaching gets automated.

Sony made a splash at its press conference with a concept Tennis Sensor capable of telling players what they're doing well on the court. The 9-gram sensor fits inside at the end of a racket handle and registers swing speed, ball speed, and spin rate by detecting motion and vibration. After a match, you can transfer data to an app and pore over it on your phone. Sony has no firm plans to release the product, but similar technology can be seen in the Zepp Sensor ($150, available now; pictured above), which can be affixed to a baseball bat, tennis racket, or golf club. Zepp says it collects 1,000 data points per second during a swing, and can display your stats with a paired app. Tennis racket manufacturer Babolat was also at CES, showcasing its Play Pure Drive racket ($399, also available now) which performs the same as its popular Pure Drive model, yet uses gyroscopes and accelerometers to collect up to six hours worth of swing data on a single charge.