Roulette probabilities Guide

Just like any other casino game, roulette offers to players different probabilities of winning or losing certain bets. These depend either on the type of bets, on the roulette house edge as defined by the type of roulette games (American or European) and on roulette payouts.

But before getting acquainted with the basic roulette probabilities, the player should grasp the fact that roulette is a game of mere chance. Every spin at roulette is seen as an independent trial, and the results of each spin will be completely random. This random character of roulette casino game is what influences the roulette probabilities most dramatically.

Roulette house edge

Roulette house edge is known as the mathematic difference between the player's true odds and actual payouts for the winning bets. This difference is what actually brings profit to the casino. For instance, the player's true odds for straight bets (bets on a certain number) are 36 to 1 for both European and American roulette. At the same time the player gets paid at 35 to 1 in case his or her bet wins. This way the player loses several dollars on every winning bet he or she makes.

This difference takes place according to the presence of zero pockets on the roulette wheel - one in European roulette and two ('0'and '00') in American. This way house edge in European roulette makes 2.63%, while that in American roulette is about 5.26% due to the presence of the second zero slot.

Types of bets in roulette

Another factor influencing the roulette probabilities is the type of bet the player makes and payouts for various bets. There are two basic types of bets in roulette:

  • Inside bets and
  • Outside bets.

Inside bets are made on particular numbers or on groups of numbers that are neighbors on the roulette layout. Straight bets - bets on certain numbers - are actually the least probable and the most risky of all roulette bets. The probability of hitting a particular number in European roulette is only 2.7% and in American double-zero roulette it is even lower - 2.63%. Straight bet pays 35 to 1, even though the true odds at roulette are 36 to 1.

Outside bets are made on larger groups of numbers as represented on the outside section of the roulette layout. One can make an even money bet on Red or Black color, Odd or Even number, Low (1 to 18) or High (19 to 36) number or bets on Columns (3 vertical lines of numbers on the layout) or Dozens (1st, 2nd and 3rd 12 numbers). Even money bets are the least risky as far as the probabilities of hitting any of these are really high - 46.37% in American and up to 48.6% in European roulette. Even money bets pay 1 to 1.

Reducing odds at roulette

Roulette probabilities can in fact be increased if the player follows the basic tips for roulette. These include:

  • Always prefer European roulette to its American counterpart. As we already know, European roulette offers better odds considering its lower house edge.
  • Better make outside bets than more risky inside ones. The former increase your chances of winning, even though the payouts for them are lower.
  • Search for roulette tables offering favorable La Partage and En Prison rules. These rules help to reduce the house edge to 1.35%.


European roulette
American roulette
No Zero roulette
Roulette Royale