Abstract: A pair of spaced, resiliently tired wheels are mounted on a base for axial rotation in a common plane, the spacing between the wheels being less than the diameter of a ball to be thrown and the rotational speed of each wheel being adjustable independently of the other. The base is supported on a universal mounting ball by means of a socket located on the base at the center of gravity of the assembly of base and components supported thereon. The universal mounting ball is supported at the upper end of an angularly bent support arm, whereby to afford angular adjustment of the rotational plane of the wheels infinitely in all directions about the common pivot of the mounting ball, between horizontal and vertical positions. Electrical controls are provided for controlling the speed of rotation of the coacting wheels.