A method, system and golf ball are provided to determine the deceleration of a golf ball and, in turn, the speed of a green. The system may include a golf ball and an offboard display device. The golf ball may include a golf ball body, a motion sensor disposed within the golf ball body to measure acceleration of the golf ball along each of three mutually perpendicular axes, and a transmitter disposed within the golf ball body to transmit data representative of deceleration. The display device may include a receiver to receive data representative of the deceleration of the golf ball from transmitter and a display to provide a representation of the deceleration of the golf ball. At least one of the golf ball and the display device may include a processor to determine deceleration of the golf ball based upon the acceleration measured by the motion sensor.