Jan

19

2016

# Odds When Playing Roulette vs Slots

Players sometimes have difficulty with the idea that slot machine results can be programmed and random at the same time. So for many years, I’ve used a comparison to roulette, where you don’t know when any given number will turn up, but the odds of the game will lead to a 5.26 percent house edge – the same as a 94.74 percent payback percentage.

Individual results are random, but the odds of the game result in 94.74 percent return to players.

That’s the way it works with slot machines, too. Every individual result is random and unpredictable, but the odds of the game lead to a programmed, predictable payback percentage.

A friend of a friend brought the issue up to me a couple of months ago, and she thought that size of slot jackpots must mean there’s a controller that sends the game to makeup time after a big win.

“I can see what’s happening on the roulette wheel,” she said. “But slots have such big jackpots. That has to be directed somehow, doesn’t it?”

I asked her to imagine a set of five roulette wheels instead of one. Where the ball lands on each wheel is a random event. She said she got that.

“OK,” I said. “Let’s pretend 00 is a jackpot symbol, and we need 00 on all five wheels to hit the jackpot.”

She caught on immediately. “That won’t happen very often, will it?”

“It won’t happen often at all,” I told her.  “Do you know how many possibilities there are, with results of five wheels and 38 numbers at all. That’s 38 to the fifth power.”

Another friend who had been listening in ran the number on his phone and reported the number was 79,235,168.

“Only one of those possibilities is 00 on every wheel,” I said. “So we’ve just ‘programmed’ a game in which the chances of winning the jackpot are 1 in 79 million-plus, but we’re using random results to get there.”

That she understood, and suggested programming an entire game with smaller payoffs for red or black numbers, or numbers on the same corner. It would be random, with a programmed payback percentage, just the way slot machines work.