Dec

28

2015

# Gaming past results have no effect on future outcomes

On most casino games, the odds are the same on every play, with blackjack being the major exception. But for roulette, craps and even slot machines, past results have no effect on future outcomes.

Nonetheless, when a streak is alive, it’s tempting to jump on. A player wrote to say he saw on a roulette table’s message board that 31 had come up four times in a row. He bought in and started betting 31 and the surrounding numbers on the layout — 29, 28, 32, 34 and 35. The streak ended, he lost some money and wondered if he should have bet against the streak instead.

If I’d been walking past and seen the four 31s on a board, I’d probably have said, “Cool, four in a row,” kept on walking and forgotten about it. The wheel has no memory – it doesn’t know what the previous numbers have been – and there’s no edge to be had by either betting or avoiding the streaking number.

Assuming the wheel is in balance, the odds in roulette are the same on every spin. Streaks happen, and the same number coming up four times in a row is just part of normal probability. It’s bound to happen once in a while, and you just happened to be there when it did.

However, if I did play, I’d probably have bet on 31 and surrounding numbers – but not on the numbers that surround it on the layout. Instead, I’d have bet on 18 and 19, which are left and right of 31 on the wheel, and 6 and 8, which are the other numbers adjacent to  18 and 19.

The theory is that if there is a balance problem causing the ball to gravitate toward 31, or if the dealer happens to be in a rhythm that is directing the ball to that area, it could increase the likelihood of the ball landing on the numbers nearest 31 on the wheel.  There’s no particular reason for the ball to favor numbers that are close to 31 on the layout, but not on the wheel.

Still, the extreme likelihood is that there is no such wheel bias or dealer rhythm, and the streak happened by chance.