Abstract: A method is provided for calculating a critical velocity of a golf ball to determine if a putt will be holed from a particular approach angle. The method provides calculating a critical velocity for a golf ball, calculating an approach angle at which the golf ball will approach a cup and computing an overall velocity of the golf ball as the golf ball crosses an edge of the cup. The critical velocity comprises both a pitch and roll dimension. The critical velocity dimensions are then compared to the overall velocity, where if the overall velocity is less than the critical velocity then the golf ball is considered to be holed.

Abstract: A method is provided for calculating an optimal putting line and stroke. The method includes receiving user input data at a processor, including at least a putt distance calibration, a green friction calibration and a targeted distance past the cup calibration; calculating a magnitude of break calibration, including an averaged pitch and roll calculation of the putting green; calculating a velocity calibration, including an averaged optimal initial velocity calculation of a putt, and combining the user input data, the magnitude of break calibration and the velocity calibration to create green reading data. The method also includes using the green reading data to create a user output display that includes an optimal putting line and stroke, where the optimal putting stroke includes a numerical deviation of a backswing of a golfer based at least in part on the golfer's normal backswing and the green reading data.

Abstract: Systems and methods are provided for calibration of a mobile device for green reading. Preferred embodiments include performing auto-leveling of the mobile device to accommodate for protruding features, and then placing the mobile device on a substantially flat surface. A first set of accelerometer data is collected of the mobile device and then mobile device is rotated in a preferred direction to collect a second set of accelerometer data of the mobile device. The collected first and second sets of accelerometer data are converted to pitch calibrations and roll calibrations, and averages for the pitch and roll calibrations are computed and saved on the mobile device. After the mobile device has been calibrated, it can be used to read a putting green.