A way to beat the roulette was kept under wraps for decades — until now.
Roulette seems random because of the way the ball bounces around before it comes to rest. The casino's "house" has an advantage of just a percentage point or two, and that's all that's necessary to come out ahead. And, the complex and chaotic bouncing of the ball is what makes roulette a very difficult game to cheat.
Until the 1970s, when a man named Doyne Farmer came up with a way to beat the wheel. He used an early computer to do the number crunching — a pretty notable feat then, since portable laptops wouldn't become common for another twenty years. But he didn't publish his findings because he didn't want to encourage cheating at casinos.
Now Michael Small, a mathematician at the University of Western Austrailia, and Chi Kong Tse, an electronic engineer from Hong Kong Plytechnic University, have developed their own algorithm for beating roulette. They submitted a paper to the journal Chaos. Farmer decided that there was no reason to keep quiet anymore.
So how did they do it? It turns out that you don't have to follow the bouncing ball exactly. Both methods are based on the motion of the ball as it leaves the dealer's hand and rolls around the side of the wheel. Those motions are actually quite predictable. It's also possible to track how many times the wheel has spun and what part of it the ball is likely to hit when it first rolls onto it.
At that point, the ball bounces around the wheel, but even then it's possible to guess the region where the ball will land. Small and Tse used the physics of friciton to predict the half of the wheel a ball would land in 13 out of 22 times. That may not sound good, but it means that they were above the 50 percent mark — enough to make a profit. Usually, a European roulette wheel is set to return -2.7 percent, but Small and Tse got up to 18 percent. A gambler willing to play a lot of rounds would profit.
Farmer's algorithm was similar, except instead of measuring the friction on the ball to determine where it would drop onto the wheel, he used air resistance.
Tse and Small note that this kind of "cheating" is probably detectable, since the only way to make it work would be with a smartphone camera watching the wheel or some kind of overhead system, which would be a bit conspicuous to say the least.
Another way the casino could catch you is via the betting patterns. Gambling author (and fellow Discovery News blogger) Scott Tharler noted that if a person bets in a certain way and keeps winning, it becomes pretty clear that there's something going on. A dealer can also throw off the roulette wheel algorithm by altering the way he or she releases the ball onto the wheel. Casinos are good at spotting that kind of thing, and people have been trying to cheat every game for decades. "The casinos are still there," Tharler said.