When do slot machines select the outcome of a spin?

After reading your columns, questions and answers for a long time now, I haven't found an answer to this question. Although many of your columns and articles have discussed and explained the RNG on slot machines, this question hasn't been raised or discussed. I'm positive that it doesn't really matter in the overall scheme of things, but I am curious.

I understand that the result of a slot machine spin is pre-determined by a RNG selection, but when exactly does it make its selection of the spin outcome? Does it select when you press the "bet one" for the first time? Does it select when you activate the reels by pulling the handle? How about when you press the manual "spin" button? When you press the "max bet" button? On the older coin machines, is the selection made when the first coin is dropped into the slot, or when the reels are activated (by 'spin,' pull handle, or 'max bet')?

Thank you... I'll continue to read your entertaining and informative columns/answers.

Terry

Dear Terry,

Thanks for the kind words about my columns.

In the early days of electronic slot machines, the program running the slot machine would select the next outcome right after finishing the current spin. The machine would then sit with the result locked in waiting for someone to play the spin and reveal the outcome. Anytime a machine sits with a result locked in, it is vulnerable to being cheated. And that's exactly what happened. Cheaters with knowledge of the RNG function were able to predict the outcome of spins.

Today a machine will not lock in a result until the player has committed to the spin by pressing Spin, Bet Max or Repeat Bet buttons (or any other button that starts the game) or pulling the handle.

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.