American Odds are the default odds at American sportsbooks. These odds are based on winning $100 for a given bet. Betting a Favorite: The odds for favorites will have a minus (-) sign, and represent the money you need to risk to win $100. So if you're betting on the Packers at -140 against the Vikings, that means Green Bay is a slight favorite. Dec 08, 2018 The probability of not drawing a spade is 1 - 0.25. So the odds is 0.25/0.75 or 1:3 (or 0.33 or 1/3 pronounced 1 to 3 odds). Moving back and forth To go from odds to probability, simply take the numerator/(denominator + numerator). In the spades example, the odds of 1/3 is converted by taking 1/1+3 = 0.25 - and now we are back to probability. Feb 28, 2021 A fractional listing of 6/1 (six-to-one) odds would mean that you win $6 against every $1 you wager (in addition to receiving your dollar back, i.e. $1 – the amount you wagered). '3:1' or '3 to 1' means that the payoff is 3/1 (or 'three times') the original bet, if it succeeds. Such a payoff reflects the bookmaker's (or counterparty's) belief that the odds of success are less than 1 in 4 (4=1+3) or less than 25%. For example, the odds of your favorite football team losing a match maybe 1 to 5. The odds of you winning a lottery might by 1 to 10,000. On the other hand, the odds of the horse you bet on winning the race may be equal to 4 to 3. What do these numbers mean? There are two types of odds ratios: 'odds of winning' and 'odds of losing'.

If you want to come out on top against the bookies it is vital that you understand the fundamentals. When it comes to sports betting there is nothing quite as fundamental as the odds that the bookies offer. Unfortunately, betting odds can prove very confusing. That’s especially true for people who are new to betting.

That’s where this article comes in. We’re going to explain exactly how betting odds work, how they are set and the differences in the ways they are displayed. After taking in all the information below, you will be much better equipped to set about making some profit.

What Do Betting Odds Represent?

At their most basic, betting odds tell you two things:

1. How much you stand to make should the selection win
2. The probability of the selection winning

Take this example. If you were looking through the weekend Premier League fixtures and saw a team had fractional odds of 2/1 (that’s decimal odds of 3.0) you would know that you stand to win £2 in profit from every £1 that you stake should the team win. You’d also know that the bookmaker who set the odds ranks the team’s chances of winning as one in every three times the game is played.

If you saw a team had fractional odds of 8/13, you’d know that for every £13 you stake, you will win £8 or profit and that if the game was played 21 times in total, the bookies think the team would win 13 times and fail to win eight times (what is known as the implied probability).

Working out an implied probability percentage from fractional odds is simple. You just divide the stake by the combined sum of the two numbers which make up the fractional odds. In the case of 2/1 the equation looks like this:

1 / (2+1) = 0.33 or 33%

For odds of 8/13 this is the equation:

13 / (8+13) = 0.62 or 62%

That’s how the maths works but when it comes to the actual odds that bookmakers set, it’s a little more complicated.

How Do Bookmakers Set Their Odds?

The basic business model of a sportsbook is fairly uncomplicated. Bookmakers set the odds and take bets on an event. When that event ends they pay out everyone who backed the winner and then keep the rest for themselves.

But, consider the following horse race.

As you can see, the combined implied probability of the selections above is 100%. From a bookmaker’s perspective that is a big problem. That’s because, presuming they’ve got the same amount of liability on each selection, they’d never make any money as they’d have to collect and payout the same amount.

So, the bookmakers will build something called an overround into their odds. Here’s a real example of a match odds market from a football match:

With an total implied probability of 101.7%, the bookmaker who set those odds is guaranteed to make a profit of 1.7% assuming that they have the same amount of liability on all three selections. Of course, it rarely works out that the bookies manage to spread their liability evenly but you need to know that when you look at a betting market you’re not simply looking at a reflection of how the bookies think the event will pan out. There’s much more going on behind the scenes.

Armed with this knowledge of how the bookmakers set their odds, you can concentrate on finding value. That is, finding a bet where you believe the odds (and therefore the implied probability) is too big. If the bookies think that a side has a 50% chance of winning but you think they’ve got a better chance than that, that’s value.

The Difference Between Decimal and Fractional Odds

You will have seen above that we’ve spoken about both fractional and decimal odds. They are just different ways of conveying the same information but they do add another layer of complexity.

All the major online bookmakers will shows their odds as both fractions and decimals so it’s important that you understand just what they are showing and how to switch between the two. Thankfully, it only requires simple maths.

To go from a fraction to a decimal is as easy as dividing out the fraction and adding one. Here’s how that looks for odds of 2/1:

(2/1) + 1 = 3.o

And using our second example from above, 8/13, it looks like this:

(8/13) + 1 = 1.62

If you want to go from decimal odds to fractional odds is similarly simple. You just minus one from the decimal odds, turn that number into a fraction and reduce it down to it’s simplest form.

Let’s take decimal odds of 4.5, this is the equation:

4.5 – 1 = 3.5
35/10 -> 7/2

If the decimal price is 1.25, you convert it into fractional odds like this:

What Do 3 To 1 Odds Mean

1.25 – 1 = 0.25
25/100 -> 1/4

Here’s a list of some of the most common fractional odds and their decimal equivalents (for a more in-depth list click here).

Key Terminology

When reading betting advice or searching for a value bet on the bookies’ websites you’ll come across some key terms relating to betting odds. To round up our article on betting odds, we’ve covered the most widely used terms to ensure you don’t get confused in your search for winners.

Stake – The amount of money that you place (or wager) on a specific bet.

Price – The price of a bet is simply another way of referring to the odds. You can either say that a football team can be backed at odds of 2/1or that their price is 2/1.

Odds On & Odds Against – Two of the key terms that you’ll hear when it comes to betting odds are ‘odds on’ and ‘odds against’. These terms refer to whether a price is greater or lower than evens. Any price above evens is known as odds against, while anything below evens is odds on.

Short and Long Odds – If something is described as being short odds it means the price is low. A long odds shot will provide you with a bigger win but is much less likely to win.

When statistical types use the word odds they mean the probability that an event will occur divided by the probability that an event will not occur, that is, odds = p/(1-p).However, in everyday conversation, people can use the word odds with a slightlydifferent but related meaning. In ordinary conversation people often mean Las Vegasor gambling odds. So you will hear terms like 3to1 or 3to2. You may also hear people talk about these matters in terms of chance, as in, the chance is 3in4 or 3in5. So what dopeople mean when they say odds are 3to1 or the chance is 3in4?

What Do Sports Betting Lines Mean? - For The Win

Consider a probability of .5 (1/2 = .5) which is equivalent to the statistical odds of 1(.5/(1-.5) = .5/.5 =1). In Las Vegas odds this would be given as 1to1, that is, one chance for to one chance against. When expressed as chance, it would be 1in2, that is, one chance in 2 of winning.

Now when a gambler says that the odds are 3to1, they mean that there are 3 chancesto win to 1 chance to lose. Alternatively, the gambler express this as the chance is 3in4,that is, 3 chances to win in 4 total chances.What they really mean is that theprobability is .75 (3/4 = .75) or that the statistical odds are 3 (odds = .75/(1-.75) = .75/.25 = 3).

You will also see Las Vegasodds of 3to2 (which is equivalent to 1.5to1, but you will never see it written this way). Oddsof 3to2 is just another way of saying that there are 3 chances of winning to 2 chances of losing.The gambler may also express odds of 3to2 as a chance of 3in5, that is, 3 chances to win in5 total chances. Whether given as odds of 3to2 or chance of 3in5 the statistical probability is .6 (3/5 = .6) and the statistical odds are 1.5 (odds = .6/(1-.6) = .6/.4 = 1.5).

The table below gives the Las Vegas (gambling) odds, chance, statistical odds and probability fora number of different combinations.

How Do Odds Work In Betting? - Investopedia