My dad worked at an arcade, and it was so fucking hard to win on a machine.

They're individually programmed. Depends on how the owner wants it set up. Some will always use the same force to pull, others vary. My brother arts them up for some casinos and was trekking me about how all the games in the arcades are rigged to pay off just enough. The one with the lights going in a circle that gives you movies if it stops on the line, its not even skill at all, when you press it doesn't actually effect the outcome