Abstract: The notion of an assymetrically configured thruster-wheel for automatic-feed ball-pitching batter/training-machines having a pair of laterally apposed axially-driven thruster-wheels; —wherein one or both thruster-wheels features a resilient circumferential-facing formed with declivities which can be regular or irregular protruding or receeding formations acting to alter the instant amount of impetus or thrust being exerted bilaterally upon the surface of a momentarily feeding ball. The thrust-wheels are axially readily detatchable from the ball-pitching thrust-motor shafts, thereby enabling coach or user to change just one or both thrust-wheels from a conventional uniform tread-surface (which thus always shoots-out balls on a predictable trajectory) to my new IM/Thrust-wheel which thereby shoots-out balls on a non-predictable trajectory.