Unofficially, the origin of the roulette has been attributed to the mathematician Blaise Pascal. In 1796, he proposed a roulette wheel with 36 numbers well distributed to give both, the casino and the gamblers, high possibilities to win. 50 years later, European casinos added the zero number to give the advantage to the casino. Besides, American casinos added a double zero to increase even more that advantage. This post will describe all important aspects and properties about the zero number (focused on the European roulette) with the purpose of stop fearing it and take advantage of it during betting sessions.

Master of 0.
Master of zero.

European roulette has 37 numbers, and Zero is the only one green. On the wheel it is located between the numbers 26 and 32. On the table is located at the top. Zero is the king of numbers!!!

The king zero.
The king, zero.

Zero’s occurrence probability for each single roulette spin is 2,7%. This means that there is an 97,3% of probability that any other number shows up. By the way 2.7% is not so much, isn’t it?

Our calculations have shown that theoretically, the maximum occurrence delay of this number is 168 consecutive roulette spins. If you play during more than 168 roulette spins and zero doesn’t showed up, it would be a good moment to begin to bet to this green number. You can read about delay occurrence. Click here.

On the other hand, it is interesting to say that zero will probably appear at least one time each 27 roulette spins. It will appear twice consecutively at least each 1000 roulette spins and so on as presented in next table. Taken into account that if a croupier releases one ball per minute it can be expected two consecutive zeros each 16 hours!!!

Computing the occurrence probability of zero for the that 168 roulette spins previously mentioned we can observed that the best time to bet on 1:1 bets is after the zero appears but before 27 roulette spins without zero occurrence. In other words, anyone can improve his or her roulette bets using all the data presented here. Let’s image you are in the casino, you have to wait for the zero, then bet on 1:1 bets with your favorite strategy and stop after 27 roulette spins. Then wait for the zero again and repeat. This will improve your probabilities of winning and avoid the feared zero.

Zero's behaviour
Zero’s behaviour

A completely new way of betting strategy with 1:1 bets is presented in the post: Using zero to win 1:1 bets in roulette game. Check it and improve your bet (click here).

Editor’s note: There exist two kind of probabilities that we have used here. First, the single probability (2,7% for zero) that is always the same each single and independently roulette spin. And second, the probability that also takes into account the number of roulette spins (computed for various and consecutive roulette spins). Maths saving the gambler’s day!

The editor
The editor