Back in my youth I knew a few types of electro mechanical slot machines where the loneliness timeout changed the odds sufficiently in favour of a decent payout that I would play only after I had seen them unplayed for that time. Walking away immediately after winning is the key.
There were one or two games that had a sufficient element of skill and judgement involved "Penny Falls" being the most common one that I could make a handsome profit on the 6 coins I started out with. I wouldn't play at all unless I was pretty sure I could win more by doing so.
Apparently called "Coin Pushers" in America I prefer the British name.
Some had weaknesses in both. I only played machines where I knew there was a weakness. Modern all electronic ones are much harder to beat and I don't bother trying. Pub Quiz machines were another favourite target.