The Ball is place into Engage in by use in the plunger, a spring-loaded rod that strikes the ball as it rests in an entry lane, or as in a few more recent games, by a button that alerts the game logic to fire a solenoid that strikes the ball. https://www.tumblr.com/businesscenterz/749401562185613312/exploring-the-thrills-of-the-batman-dark-knight?source=share