Odds Overview

The casino game is full of unpredictable. The term ‘Odds’ is often bandied about when discussing betting, whether in the real-world or in free casino online, and it’s no bad thing to understand what it actually means and the implications it has for you as a casino player. Now here comes the science bit…

Odds come from probability theory and represent the statistical chances of an event occurring. In strict terms the odds for an event happening are calculated by dividing the probability of that event happening by 1 minus that probability, or p/(1-p) where p = the probability.

For example, where an event has a 1 in 4 chance of happening that represents a probability of 0.25 (i.e. 1 /4). In this case the true odds are then:

0.25/(1-0.25) = 0.25/0.75 = 0.333333333 = 1/3.

This would be normally represented as fractional odds of 3 to 1 against. In practical terms this means if you bet £1 on the event and it happened you’d get back your original stake plus £3.

With an understanding of how odds are arrived at it’s then easier to understand what it meant by the house edge when discussing casino gambling, and why it’s important.

The house edge or house advantage is the degree to which the casino game you’re playing has odds which favor the casino over the player in the long-term, and in basic terms how casinos make their money – this does NOT mean the game is fixed against the player. What the house edge represents is the degree to which the offered odds are less favorable than the true odds of the event happening. As a simple example the true mathematical odds of winning an Evens Bet on a European Roulette game is 1.056 to 1, however it is only paid at 1 to 1. Therefore the payout is marginally less than the actual risk of the wager (and by the way, this bet attracts a very low house edge!)

What this all means in practical terms is that the most advantageous bets for any player are ones which attract the lowest house edge as the average loss per wager is at its lowest on these bets. It doesn’t mean you’re more likely to win, just that the potential payout is more representative of the risk you’re betting on.