Embodiments of the present invention are directed to devices, systems, and methods for measuring values obtained from one or more sensors installed on a player's tennis racket and/or worn on the player's body, and using those values to calculate various parameters, such as the physical position and motion of the tennis racket. Embodiments may translate the parameters and derive one or more occurrences corresponding to phases of a tennis point or drill and then generate real-time audible, visual, and/or haptic coaching prompts and other related commands and signals, for the purpose of improving a player's motor skills. Embodiments may also send and receive messages to/from other embodiments, thereby permitting a player to interact with other players, coaches, or devices, such as ball machines and cameras.