Sensors have been used for fitness tracking for a while now, but they've only recently started to infiltrate the realm of competitive sports. Take the Babolat Play Pure Drive ($400) for example. Billed as the world's first connected tennis racquet, it features sensors built into the handle that record everything from shot power and ball impact location to number of strokes, total playtime, energy, and rallies. When you're done for the day, simply sync it up to your phone or tablet over Bluetooth, or bust out the USB cable to view your stats on a PC. Best of all, it offers all the same physical specifications as the standard Pure Drive, so you don't have to sacrifice performance just to analyze it.