# Poisson Distribution

This article explains the mathematics of making a book in the simpler case of the former event. View market Jasmine Baba 16 September Leave a comment. Here is an example from the NFL:.

## Where to find the Double Chance Bet Odds?

Finally, on European shores, decimal odds are often the preferred choice. Expected value is the total amount that a punter can expect to win or possibly lose when they place a wager on the same odds multiple times over. Expected value is calculated by multiplying your winning probability with the amount you could win per wager, then subtracting the losing probability multiplied by the amount lost per bet.

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We'll only ever list fully licensed and trusted sites that have proven their safety and fairness records to the likes of:. Home Casino Sports Betting Poker. Amount you plan to bet. Check out our short odds guide written by professional sports bettors and discover how to quickly and easily calculate odds on the fly without using tools. Chance of Winning Odds Calculator OK, so you now have a way of converting any type of odds using our gambling calculator.

But what if you want to work out your own odds on a market and whether a bet is value? How do you calculate odds ratios? Related Guides Real Money.

The American Odds have two components to them, the first being the positive or negative sign, and the second being the number that follows the sign.

The sign in front of the number indicates whether placing a wager on that outcome will pay out more money then you have wagered or less money then you have wagered. The next step is figuring out exactly how much the bet pays out, which is where the numbers in the odds come into play.

Again this can easily be converted into smaller or larger size bets. The great thing about betting online is that the online sportsbooks will do the calculations for you before you place your bet. You can click on the outcome or team you would like to bet on, and then input the amount you wish to wager and it will show you your potential pay out before you confirm your bet.

The odds quoted for a particular event may be fixed but are more likely to fluctuate in order to take account of the size of wagers placed by the bettors in the run-up to the actual event e.

This article explains the mathematics of making a book in the simpler case of the former event. For the second method, see Parimutuel betting. It is important to understand the relationship between odds and relative probabilities: In considering a football match the event that can be either a 'home win', 'draw' or 'away win' the outcomes then the following odds might be encountered to represent the true chance of each of the three outcomes:.

These odds can be represented as relative probabilities or percentages by multiplying by as follows:. The bookmaker, in his wish to avail himself of a profit, will invariably reduce these odds. Consider the simplest model of reducing, which uses a proportional decreasing of odds. For the above example, the following odds are in the same proportion with regard to their relative probabilities 3: Examining how he potentially achieves this:. In reality, bookmakers use models of reducing that are more complicated than the model of the "ideal" situation.

Bookmaker margin in English football leagues decreased in recent years [6]. When a punter bettor combines more than one selection in, for example, a double , treble or accumulator then the effect of the overround in the book of each selection is compounded to the detriment of the punter in terms of the financial return compared to the true odds of all of the selections winning and thus resulting in a successful bet.

To explain the concept in the most basic of situations an example consisting of a double made up of selecting the winner from each of two tennis matches will be looked at:. In Match 1 between players A and B both players are assessed to have an equal chance of winning. The situation is the same in Match 2 between players C and D.

In a fair book in each of their matches, i. However, a bookmaker would probably offer odds of for example on each of the two possible outcomes in each event each tennis match. This results in a book for each of the tennis matches of There are four possible outcomes from combining the results from both matches: Thus the overround has slightly more than doubled by combining two single bets into a double.

This is why bookmakers offer bets such as Lucky 15 , Lucky 31 and Lucky 63 ; offering double the odds for one winner and increasing percentage bonuses for two, three and more winners. In general, for any accumulator bet from two to i selections, the combined percentage overround of books of B 1 , B 2 , In settling winning bets either decimal odds are used or one is added to the fractional odds: The place part of each-way bets is calculated separately from the win part; the method is identical but the odds are reduced by whatever the place factor is for the particular event see Accumulator below for detailed example.

All bets are taken as 'win' bets unless 'each-way' is specifically stated. All show use of fractional odds: