Nice write up of a circuit that comes up often here. Well done.

/Mark

Cost seems like a likely motivator for Gottlieb's Player Unit design. Compare the two designs for player up and ball count functions:

Gottlieb:
- one non resetting step unit with one solenoid
- no reset torsion spring
- a few plastic cams
- a generic switch stack on each cam

Bally/Williams:
- two resetting step units with two solenoids each
- torsion springs on both steppers
- no cams
- wiper fingers and a contact board on each stepper

The plastic cams were probably cheaper than the three extra solenoids and two springs. And the switch stacks may have been easier to manufacture and assemble than contact boards and wiper fingers.

The Gottlieb Player Unit certainly added some complexity but they weren't necessarily designing for the long term maintainability of the games. And the sound and light show of a resetting '70s Gottlieb multi player game is something to behold.

Building on @paulace's description I've animated the ball count circuit in various situations at:
https://www.funwithpinball.com/learn/animated-4-player-game-ball-count-circuit