## Introduction

I’m not a casino owner or gambler. I didn’t get a penny for this article from the bigwigs of the gambling business, and even on the contrary, I run the risk of causing their displeasure by teaching you how to play roulette correctly. And to further intrigue, I will say that I work as an auditor, have a PhD in economics and sell my software for fin. analysis of the largest enterprises Of Russia. Therefore, I often teach you how to save your savings, and not waste them (this is why the project was launched “Sberometer”). And yes, I did not lie in the title and I will really tell you the theory on the verge of mathematics and psychology that will allow you to win at the casino. It may not always be money, but it’s definitely a good mood!

## Who loses at the casino?

In the casino, the one who comes to earn money loses. If you go to the casino for this purpose, you have already lost! In the casino you can have an exciting time in luxury and excitement. They go to work for money. Therefore, before going to the casino, allocate an amount that you do not mind. And how to save it is my task, for the solution of which this article is written.

The second point. Never play slot machines (one-armed bandits). There is no more incompetent and stupid way to squander money than to throw coins in an iron box. However, according to the American Gaming Association, in Las Vegas casinos, 74% of gamblers prefer slot machines and only 5% prefer roulette.

What is the fundamental difference between a slot machine and roulette? In the first case, you play with a black box, which decides whether to give you a win or not. In the case of roulette, your opponent is a theory of probability with objective laws that you can observe firsthand. The non-transparent operation of slot machines allows you to put any “appetite”in them. Therefore, in various countries, including Russia, the minimum return on winnings from slot machines is set forcibly at the state level. As a rule, the minimum value is limited to 90%. I.e. if you play such a slot machine for a long time, you will find that it “eats” only every tenth ruble stuck in it. They say that in Las Vegas, on the initiative of individual casinos, this bar is raised almost to 95% (it is impossible to check, you can only believe in the kindness of gambling sharks). But more often the percentage fluctuates (at least, it should) in the region of 90%. Compare this to roulette, where the casino’s “appetite” is not 10%, but only 2.7%.

Roulette: Basics

On roulette, numbers from 0 to 36 are scattered in a circle. This is European roulette. In American roulette, there is also the 38th number – “00”. Don’t be afraid of American roulette, you are twice as likely to lose in it as in European roulette! This means that a trip to Las Vegas should be preferred to a trip to Monte Carlo or Macau (a Chinese gambling zone that has long put the legendary Las Vegas under its belt). Why is American roulette twice as voracious as its European sister? To do this, you need to understand how to win at roulette. Its size is determined not by the desire of the casino owner, but solely by the theory of probability. And it works like this.

Let’s discard the unfortunate 0s and 00s for now, and imagine that we have 36 numbers. The probability that a particular number will randomly appear is 1 in 36 (or 1/36). This means that you only have a 1-in-36 chance of guessing which number will appear (i.e., the probability of 2,78% (= 1/36 * 100%)). But if you guess correctly, you will receive from the casino 36 times more than the amount you bet.

All 36 numbers are equally colored in black and red (18 black and 18 red; only zero is green). You can choose whether to put it on” red “or” black”. If you bet a chip on red and guess correctly, the casino returns you 2 times more than you bet. Why exactly 2 times, and not 3 or 4? Because the probability of guessing by betting on “red” or” black ” is 18/36 or 1/2. Therefore, your reward will be 2 times more than the bet (i.e. equal to the denominator of the fraction).

According to the rules of roulette, you can place a chip not only on a specific number or on black-red, but also close several numbers at once with one chip. In particular, 12 numbers, 6, 4, 2 numbers (below in the article there is a picture showing how this is done on the game table). And in all cases, if you guess, the payoff will be inversely proportional to the probability of guessing. So, by closing 12 numbers, you will get 3 times more chips than you bet (12/36 = 1/3); put a chip on 4 numbers at once, get 9 chips (4/36 = 1/9) and so on, the principle is clear – less chance of winning, more chips you get.

If there were only 36 numbers on roulette (by the way, the sum of all the numbers from 1 to 36 is 666, which is why roulette is called the “ferris wheel”), then we could play for hours on end in the casino, staying with our money. As shown above, winning would exactly balance out the probability of losing. But the casino is not a charitable organization, so it wants to take a bite out of your pie. To do this, we added 37 numbers to 36 numbers — ” 0 ” (European roulette). And greedy Americans also have the 38th – “00”. The rules for calculating winnings remain the same, as if we have 36 numbers. It turns out that the 37th (and 38th) number is the casino’s income. Now the probability that your number will fall out is 1/37 (or 1/38 in the American version), but you will still get 36 times more than you bet. It turns out that on average, the casino receives 1 ruble out of every 37 rubles that you bet on roulette. Casino revenue— 2,7% (1/37*100%); and from American roulette — 5.3% (2/38).

## How much does the casino earn on me?

Yes, when playing roulette, you pay only 2.7% to the casino. But this is so small, you say?! The supermarket’s mark-up on food products can be 20% or 30%! Why, then, are gold walls, marble floors, and free booze in a casino instead of a supermarket? Everything is simple. The store bears the cost of delivering the goods, storing them, etc. And the casino takes your bill and, figuratively speaking, cuts off the 37th part from it, without leaving the gaming table. Money flows like a river, and a small stream leaving this river in favor of the casino turns into a very big lake with goldfish on the fazenda of the owner of the gambling establishment. So why am I writing this article, if 2.7% is guaranteed to be given to the institution, the game is obviously losing? Because you can lose in different ways. You can lose all your money in one moment, or you can spend the whole evening enjoying your victories, getting sharp, but mostly positive emotions. How-read below.

A story from the 90s. In Moscow, the first casinos appeared in the best traditions of capitalism, pompous, with free drinks, but the minimum bet is too big for ordinary citizens. But it wasn’t there, where our people didn’t disappear! There were tricksters. They came to the casino two at a time, pretending they didn’t know each other. One bet on black and the other on red at the same time. As you can see, in 36 cases out of 37, one of them won, and exactly as much as the second one lost. That is, in total, they would remain with their money. What’s the catch? And the booze is free! True, they quickly learned to recognize such drunken beggars and display them under white pens.