If you want to play roulette “like a pro”. You must understand the percentages and probabilities behind the game. The first thing to understand is the fundamental formula for probability:
The probability of an event is the number of ways. That event can happen divided by the total number of possible outcomes.
Therefore, a probability is always a fraction—a number between 0 and 1. It can be expressed as a fraction, a decimal or a percentage. You can also express a probability in odds terms.
With roulette, a bet on the ball landing on the 1 has a probability of 1/38. You have 1 possible outcome that wins. But you have 38 possible outcomes.
That 1/38 can be expressed as a fraction. As I’ve just done. Or it can be expressed as a decimal or a percentage. Which would be 0.0263 or 2.63%.
If you wanted to express it as odds. You’d express that as the number of ways you can lose versus the number of ways you can win in this case, 37 to 1 UFABET
If you compare the odds of winning to the payout odds for the bets. You’ll find a discrepancy.
A bet on a single number (like the bet on 1) pays off at 35 to 1. Since the odds of winning are 37 to 1, there’s a clear difference. That difference can be quantified as a percentage. An average amount the casino expects you to lose per bet mathematically.
To find that average, you just assume 38 theoretically perfect spins and calculate how much you’ll win or lose on them. Since you’ll lose 37 times and once for 35 units. You have a difference of 2—average that out over 38 spins and you get an average of 5.26% lost per spin.
That’s the house edge.
It’s a long term expectation, and in the short run, it doesn’t matter much.
But the casino is playing in the long run, and if you think long term, you will be, too—eventually. The lower that house edge is, the less money you’ll lose over time.
On a European or single-zero wheel, the house edge is significantly lower—2.70%.
If you spent a week playing an American roulette game and a week playing a European roulette game, you’d lose less money during your week playing European roulette (probably).
As it turns out, the payoff odds versus the odds of winning on almost all the bets available at the roulette table gives the same edge—5.26% or 2.70%. There’s only one exception, and I’ll cover it in the next section on roulette bets.