You are walking through your favorite Las Vegas casino when you spot a roulette wheel.
You look up at the digital board above the wheel and notice that the roulette ball has landed on a black number 9 times in a row. One color, 9 times in a row! That is crazy! It can’t happen again can it?
Would you stop at the table and put a few chips down that the next spin would land on red? I think I probably would.
Why is that?
I guess it has something to do with our understanding of the law of averages. The ball can’t stop on a black number every single time. It eventually has to stop on a red one.
But what makes me think that after 9 consecutive stops on black it is a sure thing to land on red?
Do I actually think the roulette ball has some kind of memory and recalls that the last 9 were black so it should probably give red some love? Do I really think the roulette wheel has a conscience that says it needs to even out the black and red spins so the next spin must be red?
I can’t really think that, can I??
Turns out I am not the only one who thinks this way.
In 1913 at the Monte Carlo Casino, a big commotion was made when one roulette table hit 16 black numbers in a row. Word got out about what was happening and people started rushing over to the table to put a big bet down on red.
But the wheel stopped on black a 17th time. Then an 18th. And a 19th.
Up it went to 26 black numbers in a row, earning the casino millions of dollars in just a few spins of the wheel.
People were convinced that after so many black spins, the wheel was more likely to stop on a red number.
This line of thinking has a name and it is appropriately known as the gambler’s fallacy.
See, if you flip a coin 1,000 times, close to 500 flips will result in heads and 500 will land on tails. We assume the same thing also will happen for 10, or 20 flips. But that is not the case.
In the short run, the results are actually quite imbalanced. You’ll likely have runs of five or six in a row landing on the same side of the coin. People misinterpret what happens in the long run for what ought to be happening in the short run.
That is why people playing slot machines will guard the machine with their lives if it hasn’t paid off for a few hours. They don’t want anyone else to use it because they just know it is due.
This explains why I would really want to bet on red after 9 roulette spins in a row have landed on black. When in all actuality, each spin is independent of the last and we start with a clean slate. Black is just as likely to come up next as is red, no matter what my gambling brain might be telling me.
(Photo credit: Wikipedia)