We’ve discussed elsewhere how casino gamblers are often very superstitious about their favorite games. Sometimes, this superstition manifests itself in harmless ways. If you really only want to play at slot machines that face South or if you want to carry a lucky rabbit’s foot with you that’s not really a big deal. What is a problem, however, is when superstition causes players to do something counterproductive.

The best thing that any gambler can do to maximize wins and minimize losses is to accept the fact that all casino games are governed by inviolable mathematical rules and statistical models. The ‘house edge’ is unchanging for most games and there’s no way that luck, superstition or guesswork can overcome that. The games are already designed in such a way that the ‘house’ always has the ‘best of it’. The last thing you want to do is to give them more of an edge by ignoring or being oblivious to the math that underpins it.

Whether you play it online or in a land based casino, few games offer the mathematical certainty of roulette. European roulette has one ‘zero’ and offers the player a 1 in 37 chance to hit any number. American roulette has two ‘zeros’ and offers a 1 in 38 chance to hit any number. Assuming the wheel is properly balanced and maintained (not an issue online of course) this math is set in stone. Since a bet on a single number pays 1 to 35 in both games (assuming that you’re not getting ‘short pay’ prices) you’re obviously better off playing European roulette. These are all important topics but ones that we’ll hit in the future.


One of the more amusing forms of casino acquiescence to the superstition of gamblers (or their lack of mathematical knowledge) is found in roulette. Pretty much every casino roulette wheel has a display–more often on a digital display today and not the LED tower employed in the past–that shows the last numbers rolled in sequential order. The casino is no doubt happy to help players indulge their superstitious or misguided beliefs about the nature of roulette.

Simply put, every spin of the roulette wheel is an independent event. Except for the rare instance in which there is a ‘wheel bias’ every spin of the wheel is also completely random. Therefore, probability theory 101 has taught us that what happens before an independent event has no impact whatsoever on the outcome. This means that knowing the numbers that have previously been hit have no value whatsoever. The casino might as well just display random numbers on these ‘previous spin’ screens.

To think otherwise is a well known logical fallacy called the ‘Gambler’s Fallacy’. It’s the erroneous belief that a random, independent event is somehow influenced by previous random, independent events. Or to put it another way:

Reasoning that, in a situation that is pure random chance, the outcome can be affected by previous outcomes.

The ‘Gambler’s Fallacy’ is so named due to it’s prevalence among casino gaming enthusiasts. As it applies to roulette, it means that you don’t need to worry about a number having appeared recently, nor should you concern yourself with a number that *hasn’t appeared* and is presumably ‘due’. You don’t need to worry if a certain number of even or odd (or red or black) numbers have appeared in a row. None of this matters.

No matter what your preferred casino game it’s a good idea to get a grasp on these basic probability concepts. It’ll help you win more and lose less at the casino or online. Specific to roulette, don’t worry about what numbers have shown up before. Just focus on the individual spin.