Hi all,
I was incredibly surprized when a search of the archives turned up zilch on this, so here goes.
My girlfriend has recently acquired an electroically- controlled-mechanical slot machine (still has wheels like in the old days, but the wheels are driven by motors, and controlled by computer). At certain times (determined by a random number generator) the machine enters “bonus mode”, where it pays massive amounts of coinage out for simply getting the “free spin”.
The disturbing part about it is, try as you might, you are unable to stop yourself from hitting the free spin! In other words, you always win. This is the root of my question. How is it possible for a machine to control the odds of hitting a point dynamically?
My first thought was that it altered the wheel. This would be easy for a video slot machine, but proved impossible for this model.
Secondly, I thought that it was delaying the spin stop (after you push the button) to hit the right point. After timing the spin both during and without “bonus mode” though, I determined that this also wasn’t changed.
Third, I thought it might be changing the spin speed (to somehow influence the odds?) After turning my trusty strobeascope on it though, I found that this also wasn’t the case.
I’m now fresh out of ideas, so I humbly turn to you kind citizens for help.
The motors in a slot machine are stepper motors, and can be controlled precisely by the computer. The computer can actually stop the shaft of the motor in very fine increments. Depending on the motor, the resolution could be as high as 1/1024 of a revolution. Certainly the computer can easily stop it on any given symbol.
In fact, that’s how slot machines work now. The outcome is pre-determined by the random number generator in the slot machine, and the computer simply manipulates the reels to show what it had already decided on.
What this means is that there is no relationship between the symbols on a reel and the actual odds of hitting a certain combination. If the slot machine had three wheels with three symbols each, you would think that each individual combination had a 1/27 chance of coming up. In fact, the software could be programmed to only put up three cherries once every 10 millions spins.
With the reels under positive control, the computer can do other insidious things, like make you think you almost hit the jackpot by having 4 of 5 reels come up with a bar and the fifth one JUST missing it. Or putting the jackpot combination on the payline you didn’t select, in order to goad you into putting more money into the machine.
Modern slots are generally bad news. Stay away from them.