Books have been set forth on this topic, and the debates and discord about where the "hot" one armed bandits are placed in a casino are still happening – over sixty yrs after one armed bandits were first added to the gaming floor in gambling houses.
The quintessential rule is that the most favorable one armed bandits were put just inside the main door of the casino; so that people going by would be able to see actual jackpot winners … be convinced to come unto the gaming floor and play. Our finding is that this is definitely no longer the case.
Just about all of the large casinos these days are herculean complexes … now you can’t see inside from the sidewalk, so there is no longer a reason to put the ‘loose’ one armed bandits in close proximity to any entrances.
Another classic rule is that loose slots are positioned on the major aisles in the casinos, again so that more persons could see winning jackpots and be encouraged to play. Interestingly though, we find that this also isn’t a universal rule any more.
What casinos found over the years is that people walking down the busy aisles were frequently on the way to somewhere else. If they played slot machine games at all, they would simply put in their loose change because they happened to be walking by. Win or lose, they would very often not stop to keep playing. And the last thing a casino wants is for someone to win a jackpot by playing only a few coins and then not stay to put it all back in!
These days, casinos are constantly changing their perspective about where to place the loose one armed bandits.