What people don't often know is that on the old MPU3 boards like here, you would 'block' certain progress in a different place on the feature board or gamble ladder depending on which of the top dip-switches you had on, i.e. 72-88%.
I recall this lad who lived downstairs from me in flats years back who was nearly in tears, told me just done his bollocks, over £180 quid, trying to win a £5 jackpot on a 10p machine. Turns out he was gambling a 4 quid win for the top Melons and it simply wouldn't win, whether on number 2 or 11, it would be 1 or 12 every time. I spent a few minutes explaining it was impossible on the 72% they had it on, he could put the US national debt through it and it still wouldn't win.
That brings us to the points
@ChopleyIOM raises in his video, the morality or even legality of the old AWP's and the useless twats called BACTA (Bent Amateurish Conning Thieving Arseholes) who administered the industry. Basically, certain settings would make some of the things displayed on the glass impossible therefore it was false advertising to the player. This still hasn't changed to this day, except after that geezer went to the press when the programme code was revealed which proved pre-decided gambles and then stickers were added which warned players the gamble may not be true odds or whatever.
I owned a couple of Cub Machines from this era, used them as money boxes and had the bottom open with the dip switch taped down so I could re-play the 'backing' coins. I spent hours doing stuff like
@ChopleyIOM in this video, getting the things so 'happy' they were even chucking 4OAK wins in every 20 spins.
There was one £150 JP machine I had that when on the top 88% setting would ALWAYS drop the 3 Cashpot symbols in between 80.10 and 81.00 and then let your next gamble go to £50 for afters, yet you couldn't get past Win Series EVER on the feature ladder which paid £30 - £40 (or £50 if you took it after the Cashpot). The next one above it was Bar Win, then 'match stoppa' (which would mean jackpot if you were good at it) and finally Jackpot. You could get these on some lower percentages setting though, but the cashpot would always fill to 150 and not come in at 80-81 quid.
The whole Club Machine thing was a huge con IMO, and unless you were like Smedley and his mates you never had a chance.