The Big Number Roulette Strategy (Does It Work?)

People Playing Roulette Casino Game, Numbers in Background
I recently read a post by another gambling writer who offers a roulette strategy. He makes the following claim about this “big number roulette strategy:”

If you use these 2 roulette tricks and combine them with my money management advice, you might reduce the overall negative expectation of the game.

He starts the post by rambling about dice games during the time of Caesar, which seems to be a digression. He follows up by explaining the difference between a roulette trick and a roulette system.

The conclusion he comes to is that there isn’t much of a difference between roulette tricks and roulette systems. A trick, basically, is less complicated than a system.

The idea behind the big number roulette strategy is that you look at the numbers which have hit over the last 20 spins. These are usually posted digitally above the roulette table. You look for a number which has hit multiple times.

The number that’s hit the most often is “the big number.”

When you sit down at the roulette table, you start betting on that big number.

Here’s an Example:
You sit down at the roulette table, and out of the last 20 spins, the number 20 has come up 3 times. The 8 has come up twice, too.

Since both these numbers are “repeaters,” you’re going to bet on each of them each spin.

The Size of Your Bets Using this Roulette Trick

Placing Casino Chips on Roulette Table Number This would be a boring roulette trick if it were this simple, so the blogger includes some additional advice about how to size your bets.

If you’re betting the table minimum, you just place the minimum sized bet on each number.

If you usually bet more than the table minimum, you divide the size of your usual bet by the number of bets you’re making. You’ll rarely be betting on more than 3 numbers at one time, so your bet sizes will usually work like this:

If you’re betting on one number, you’ll just place your normal sized bet.

If you’re betting on 2 numbers, you’ll just bet half of your normal sized bet on each number.

If you’re betting on 3 numbers, you’ll bet about 1/3 of your normal sized bet on each number.

When to Stop Betting with this Trick

The next part of the trick to keep in mind is that you’re supposed to watch the “scoreboard.” When a number disappears from the scoreboard, you stop betting on it.

Stop Sign

It’s possible that at some point there won’t be any repeaters on the scoreboard. When that happens, you stop betting until one of the numbers has started repeating.

His premise is that it takes self-discipline to stop betting. This is true, although—as I’ll explain shortly—it’s not impressive to exercise self-discipline when you’re using a faulty strategy.

The only advantage to sitting out a few rounds of betting is that you’re putting less money into action. Anything you can do to reduce the number of bets you place per hour lowers your predicted hourly loss rate.

Negative Betting

He goes on to explain that some players prefer to bet against numbers which have come up multiple times already. He calls this “negative betting.”

The language he uses to describe this is interesting. He says that this approach is “just as valid” as the strategy he’s presenting.

On this, I agree with him.

Here’s Why:
Betting on a number because it’s come up repeatedly does nothing to improve your odds. Betting against numbers that have already come up does nothing to improve your odds, either.

I’ll have more to say about that shortly, too, but I want to make sure I do a good job of making the case for the big number strategy before offering my critique of it.

Multiple Numbers Repeating a Different Number of Times

I guess one of the questions some roulette players ask about this system is what they should do if multiple numbers have shown up repeatedly but with a different frequency.

For example, if one number has come up 4 times, another number has come up 3 times, and a 3rd number has come up twice, should you change your betting strategy?

Roulette Wheel with Ball, Guy Icon Thinking with Question Mark

The writer’s advice is to stick with the same flat betting amount on each number. The idea is to keep it simple.

Then he offers the most honest piece of information in the entire description of the strategy:

Nothing you do is going to change the fundamental math or probability—that you have a 1/38 probability of winning a single-number bet on an American wheel, and you have a 1/37 probability of winning a single-number bet on a European wheel.

It’s almost as if this writer has multiple personalities, because the implication is that you are doing something worthwhile by betting on the number that’s come up repeatedly.

But according to his statement about the probabilities, you could just bet on any number you want every time you spin the wheel. And there would be no difference.

Other Bets Besides the Straight Up Bet

He goes on to explain that you’re not locked into making the straight single-number bet. That has the best payout (35 to 1), but you can place other bets based on the big number that will hit more frequently, albeit with lower payouts.

Let’s say, for example, that the black 10 has come up repeatedly.

You could place the following bets, all of which pay out at even money—and all of which win closer to 50% of the time:

  • You can bet on black.
  • You can bet on even.
  • You can bet on low.

If you place all 3 of those bets and that black 10 hits again, you’ll win all 3 bets.

You could even place those bets along with some more aggressive bets, like a bet on 1-12, which pays off at 2 to 1. You could even bet the single-number bet in addition to these other bets.

Of course, if you have multiple repeaters, you might be prevented from making some of these bets. If there’s a red repeater AND a black repeater, you wouldn’t bet on black (or red).

Some Tips to Keep in Mind When Using the Big Number Roulette System

He also offers some more tips from his perspective as a “conservative player:”

Silhouette Man Sitting Reading Book on Roulette Tips

  • Don’t make too many bets at the same time. (He doesn’t explain how many bets are too many, though.)
  • Don’t increase the size of your bets when you’re losing. (This is good advice, actually, although it doesn’t matter as much as you might think. After all, when you’re playing a negative expectation game like roulette, you’ll lose all your money eventually anyway if you keep playing.)
  • Don’t bet so much money that you’ll be upset if you lose it. (This is also good advice, actually. You shouldn’t be gambling with money you can’t afford to lose, ever.)
  • Keep your gambling money in a separate bank account. (This is meant to prevent you from mixing your living expenses with your gambling bankroll. I think this is overkill. It reminds me of some of the strategies alcoholics use to try to reign in their drinking. Those strategies never work, by the way. I promise.)

What’s Wrong with this Roulette Strategy?

This post about the big number roulette strategy was one of the stranger posts about roulette strategy that I’ve ever read, because it never gives any justification for why you would want to use this strategy.

I can surmise—based on reading one of the blogger’s books in print—that the idea is to take advantage of a biased wheel, but he doesn’t explain that in the post. He just says, hey, here’s a neat way to bet on roulette that might decrease your negative expectation.

His strategy doesn’t do that, by the way, but I’ll finish his argument for him below:

The idea behind the big number roulette strategy is to take advantage of it when a specific roulette number is “hot.” You’ll read stories about how certain roulette wheels aren’t structurally perfect. If a number is coming up repeatedly, it MIGHT be because of an imperfection in the wheel.

And by betting on that number, you’re taking advantage of that imperfection.

How Realistic Is It That You’re Going to Find a Biased Wheel in Today’s Casinos?

At one time, casinos did have biased roulette wheels on their floors. You can read numerous accounts of gamblers not only getting an edge but winning lots of money taking advantage of such biased wheels. Some gamblers won millions.

Here’s the thing, though:

Modern casinos run a tight ship. Casino equipment is replaced regularly and moved often. Even if you found a biased wheel, it might not be in the same location during the next shift at the casino.

I’d put the odds of actually finding a biased casino at slim to none to begin with.

How would you know if a wheel were biased?

It would take more than 20 spins to have any kind of confidence that a wheel is anything other than random. In fact, it would take more than 200 spins, too.

Roulette Wheel in Motion Spinning

You couldn’t reliably expect to have an idea about an imperfection on a roulette wheel unless you observed at least 2000 spins.

Even then, your confidence level should be low. You’d need 5000 to 10,000 spins to realistically predict which numbers come up more often than they should.

Let’s assume that you can observe an average of 50 spins per hour on a roulette wheel. This means a minimum of 40 hours of observation clocking the wheel before you can have any confidence in your results.

You’d be better off, though, with between 100 and 200 hours of observation.

And since the casino moves the wheels around from time to time, you’d need at least one—possibly 2 or 3 confederates to help you clock the results.

That’s a full time job for all 3 of you.

But consider this, too:

You might spend all that time clocking a wheel only to find that there’s no bias at all.

Or you might spend that time clocking a wheel to find a bias, but it’s not enough of a bias to get an edge over the casino. After all, on an American roulette wheel, the house edge is 5.26%. Even if there’s enough of a bias to cut that in half, you’re still facing a significant edge.

Hot Numbers, Cold Numbers, and the Gamblers Fallacy

The Gamblers Fallacy is the belief that previous results affect subsequent results in independent trials.

A spin of a roulette wheel is an independent event. The probability for an independent event is simple—you divide the number of ways you can win by the total possible number of outcomes.

On a roulette wheel, there are 38 different numbers. With a single number bet, only one of those numbers can win, so the probability is 1/38.

The payoff is 35 to 1, so it’s obvious how the house gets its edge. You’ll lose slightly more often than you should to break even, and the house gets to keep the money.

Roulette Wheel, Ball, Arrows Repeating Cycle

But if the ball lands red 5 times in a row, you’d be forgiven for thinking either of the following:

  1. You should bet on red, because red is hot and more likely to come up on the 6th
  2. You should be on black, because black is overdue. It’s unlikely to see red come up 6 times in a row.
The truth is, though, that the probability doesn’t change on that next spin. Yes, it is unlikely to get a red result 6 times in a row. But you’re not betting on red coming up 6 times in a row. You’re betting on the outcome of the next spin.

Betting on a number because it comes up more often in a set of 20 spins doesn’t change the probability.

Betting against that number doesn’t change the probability either.

Thinking that it does is engaging in the Gamblers Fallacy.

The Problem with So-Called Roulette Strategies like This

Even though the post I read explaining the big number roulette strategy includes multiple disclaimers, it also leads you to believe that you’re somehow going to get an edge over the casino. The author even stated early in the post that even if you can’t get an edge, you might lower your negative expectation.

He contradicts himself later in the post, but at least he was accurate in that later section.

Roulette Board and Wheel

You can’t get an edge at roulette. The house edge for the game is almost carved into stone. It’s not something you can change by following trends.

It might be fun to bet this way.

But in no way does it reduce the house’s inherent mathematical edge against you.

Keeping your gambling funds in a separate bank account, watching the size of your bets, and betting on a number that’s come up repeatedly in the last 20 spins does nothing to help you succeed at roulette.


The big number “roulette trick” is just a strategy for betting on roulette that exemplifies the Gamblers Fallacy in action. A big number roulette bettor looks for a number or multiple numbers that have come up repeatedly in the last 20 spins. He then places single number bets on that number. Or he makes broader bets based on the color of the number, or whether it’s even or odd, or whether it’s in the 1st, 2nd or 3rd dozen.

The problem with the strategy is that it doesn’t work in the long run.

Sure, you can sometimes hit a win with a strategy like this.

But your probability of hitting a win with a strategy like this is no better than it would be if you just chose a different number every spin of the wheel.

I don’t like posts that promote this kind of betting strategy, even when such a post includes disclaimers. I want to be really firm about this:

I don’t recommend using the big number roulette strategy.

It doesn’t work in the long run, and it offers no advantages over any other “strategy” for the game. It might be entertaining, but I don’t think it’s much more entertaining than just playing roulette haphazardly.