Roulette ball in wheel

Why Don’t People Always Just Bet on Black in Roulette?

Roulette, as everyone knows, is a casino game that is based on pure chance. There aren’t any strategies to make the ball land on the number or even color of your choosing. The only strategy that can be implemented on a roulette table, in fact, is knowing how to bet. 

It takes a fair amount of knowledge to bet optimally, but when you get down to it, isn’t there a super simple strategy to make sure that you win back twice your money almost half the time? 

Betting on black (or betting on red, for that matter) doesn’t exactly bring in as much as, say, winning on a number – it’s basically an even bet, which means you get twice your bet back – but at between a 47% and 48% chance of winning, depending on whether you’re play a US or European table, doesn’t that mean you’ll be doubling your money every second spin so wouldn’t you be guaranteed to walk away with an extra 20% to 25% of the cash you had when you sat down at the table?

It’s not a glamorous win, sure, but is it not a sure thing?

No, as it turns out.

Roulette wheel

But Why?   

There are two fundamental misunderstandings at play here. Two misapprehensions of the basics of roulette that completely tank this seemingly unbeatable strategy.

  1. Understanding statistics. A 50% chance of winning does not, and I repeat, does not mean that 1 out of every 2 spins will result in a win. What it means is that each individual spin has a 50/50 chance of landing on red or black, with each spin having no relation whatsoever to any other. By the law of statistics, half of 500,000 spins, say, will come up black but on a smaller sample size of 5, 10, even 50 spins, even with the exact same odds, may well result in only a quarter of the spins coming up black or even none whatsoever. 50%, in short, is never a guarantee of 1 in 2 going your way, but that every turn you have only a 50% chance of things going your way. The difference is subtle, but it’s monumental.

  2. Understanding the house advantage. Crucially, if even 50% odds are no guarantee of winning 1 out of every 2 spins, 47% or even 48% odds basically completely blow apart any hope of this strategy working. The fact that you have very slightly less than a 50% chance of winning each spin (thanks to the addition of a green zero slot on the wheel) is done to make sure that overall, the casino will always bring in more money than it gives out. These tiny 2 or 3 percentage points may seem insignificant, but they are the sole reason why casinos offer roulette tables in the first place: to make a profit. This “house advantage” is built into every single casino game and it ensures that the more you play, the more likely you are to lose. It’s why budgeting a set amount of money you are willing to spend on any night out at a casino is the keystone of responsible gambling. 


All this said, though, if you do want to be a more conservative gambler and you’d prefer to win a little than lose a lot, on average, then that near 50% chance given by betting on black is a safer bet than almost any other bet you can make in a casino. Just remember, though, that even the safest, “surest” bet is always against you.

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