How does the RNG in a keno machine work?

Read every letter you send out and feel more informed after each read. Thanks!

My question is on RNGs and trying to picture in my mind. I know, I understand the idea but just how it works is hard to get straight in my mind. I know random means just that, but should I picture a keno ball dispenser on a huge scale and after one number drops, will it take a bit to get back in the system or is that number always in the RNG ready to come out as I assume is true? The other thing is does the cycle always run even though nobody is playing the machine?

Dave

Dear Dave,

Thanks for the kind words about my column.

The RNG in a keno machine works in exactly the same way as the blowers you see on a nightly lottery draw. Once a number has been drawn in a particular drawing, it cannot be drawn again. (This is known as sampling without replacement.) On the next drawing, all the numbers used in the previous drawing are available again.

The RNG runs even when no one is playing a machine. In the very early days of computer-controlled slot machines, the machine would determine the outcome of the next spin right after the conclusion of a spin. It would then sit with that result locked in, waiting for someone to play it. RNG cheats had all the time in the world to figure out the locked-in result -- and they were able to figure it out. Slot regulations were then changed to require the RNG to run continuously and, thus, make it harder for cheats.

Best of luck in and out of the casinos,
John

Send your slot and video poker questions to John Robison, Slot Expert, at slotexpert@comcast.net. Because of the volume of mail I receive, I regret that I can't reply to every question.