Quoted from jrpinball:Probably one of the major reasons they radically changed the design.
I'm a Gottlieb guy, but IMHO, Bally had the best score reel design in all aspects.
And Williams. Their designs are very similar. Williams and Bally are Japanese cars to Gottlieb's German cars here. Overly complicated piece of engineering, fiddly to get dialed in and keep dialed in.
Williams and Bally, once they are dialed in, are rock solid. I have a Bally Surfers that was basically stored for near 20 years. I fired it up and the reels worked perfectly. Try doing that with a decagon.