Needed: Compensating Bat

I need a softball or whiffleball bat that rewards gentle use but somehow becomes spongy or nearly useless when it is used with force, so that adults and children could seriously play the same game.  When you hit the ball hard, it only goes a little ways; when you hit the ball softly, it goes about the same distance.

There would still be a need for compensation in other areas, e.g., running speed, throwing strength.  Measures of galvanic skin response, focus, and direction might measure and reward effort rather than actual speed, strength, or demonstrated accuracy in an electronically based game.