A device for assisting and training golfers with their putts. The device includes an elongated section configured to be placed on the ground where the golfer intends to make his backswing for a selected put. A vertical section or “backstop” is configured to be placed at selected locations along the elongated section to corresponding to different putt lengths, and therefore different backswing lengths. A distance scale may be printed on the elongated section. Light projection devices may be included to project a predicted ball path. A backswing speed indicator system may also be included.