To clear the confusion on Mad World..yes,it is a multiball.But very different to the likes of Star-Jet and others.By hitting a certain target allows the locked gate to open in the alley on the right.The ball lodges in the upper step and a second ball can now come into play(remembering you have the old manual ball-lifter).Now,you play the second ball and,if hitting corresponding targets,the first ball will move down the alley to the next step...if successful,it can go all the way to the shooter's lane with the other ball still in play.Now,you have a choice-shoot the ball into play while the other ball is still active or hold that ball and play the other by itself until it drains and then shoot the first ball-the ball count remains.I think my machine may have a fault with the gate as,when the target is hit to allow gate to open,it doesn't lock properly afterwards(supposively when a ball enters the alley,the gate should not re-open)...I'm not complaining as I put 4 balls in it and have played it with 4 balls all on the playfield at the same time(a 4-ball multiball in 1964?!!).I did some research and I think the only other machine that has something like this may be Capersville(but doesn't operate quite like that...kick-out disengage the alley).Someone mentioned Four Million BC from 1971 but not sure about that.I think Bally had two concepts for multiball back then-one like Star-Jet which they continued while the one on Mad World was abandoned.
N.B.-You get bonus points for clearing the alley and returning to the shooter lane-a rollover at the top that scores points,then 4 steps the ball lodges,then another rollover..that one being the big pay-off.Definitely,a totally different machine when running 4 balls(but that wasn't what it was designed for...like I said,not complaining!