Hot and Cold Numbers in Roulette

The statistics you can see here are shared by Pragmatic Play, a well-known casino game provider. This data is pulled directly via their own API, which means that we have real-time access to the results of the last 20 spins from different online roulette tables. Our team then collects this data and processes it using set timeframes, like the past 20, 50, 100, or 500 spins, and works out which numbers appeared the most and which numbers appeared the least. With this analysis, we can create a list of hot and cold numbers (the frequent ones and the ones that barely showed up), so you can have insight into the recent game history and patterns.

Generally, there are two types of games: those where past outcomes can influence future ones, and those where past outcomes don’t influence the future. Roulette is the second type of game. It’s what we call an ‘independent event’ game. In other words, it means that each spin is completely separate from the previous ones, and the odds reset with each spin, so the chance of landing any number is the same every single time, regardless of the past outcomes.

We can back this up by a basic probability theory that has been around since the 1900s. Without getting too technical, we’ll explain it by the following formula: P(A ∩ B) = P(A) × P(B)

Still confused? We have an even easier example.

Imagine flipping a coin. Every flip gives you a 50% chance of heads and a 50% chance of tails. Even if you get 49 heads in a row, the 50th flip will still have the same 50% chance of landing heads or tails. Nothing changes. Each flip is unaffected by what happened before, regardless if you played it once, 10 times, or 10,000 times.

Roulette works in the same way. If we take European (single-zero) roulette, for example, we can calculate the exact chance of winning. The probability of hitting a red or black number on any spin is around 48.64% (due to the zero). That doesn’t go up or down, no matter how many times you spin the wheel. Each result is new and independent.

You can try it out for yourself with a random number generator or even simulate real spins. For example, we ran 1000 spins and logged the numbers, and this is what we found:

In the graph, you can see the ‘cold’ numbers – or the ones that were chosen the least often. We placed straight bets of ₹100 on each cold number using a starting bankroll of ₹10,000. Then we ‘spun’ the wheel 500 times. These are the results we’ve got:

There was absolutely no improvement in the outcomes. Betting on cold numbers did not increase our winnings. The house still had its edge, and each number still had the same 2.7% probability of appearing on each spin.

This proves what mathematicians have always said: past spin results do not affect future spins. Just because a number hasn't shown up in the last 500 spins doesn't mean it’s “due” now. Betting on hot numbers would have provided us with largely the same result.