It's sometimes not clear, but dip #3 is for whether your lane has a rocker arm release method or a simple lever that pops up to release balls. The rocker arm version will need 9 balls. the single arm will play with 1 ball, but can have more. it just has a sensor that counts how many balls has been released, then drops back down after 9. It will usually not work with 9 balls, however, because the balls will back up past the ball count switch and never register the end of the game. I solved that for one customer by moving the release mechanism closer to the front of the game so that all 9 balls could fit (they didn't want it to play as single ball)...