## How Do Betting Odds Work? What Do Odds Mean?

Betting sites in the UK usually show the odds they offer in one of two formats: Fractional or Decimal.

Fractional Odds
Fractional odds are the most common, are almost always used on the High Street, and are the usual default format on British betting websites.
Fractional odds look just like fractions, for example 2/1 (spoken as "two to one") and 5/2 (spoken as "five to two").

Decimal Odds
Decimal odds are becoming more common, because it is easier to express more precise odds. This is particularly important for odds comparisons, and for betting exchanges like BETDAQ and BetFair which need to handle very small changes to odds being offered. Unsurprisingly, decimal odds like just like decimal numbers, for example 3.0 and 3.5.

Probability
Bookies seldom use probabilities but it is useful to understand them. Probabilities are expressed as a number out of one hundred, followed by the percentage symbol ("%"). A probability of 0% means that it will never happen, 100% means that it is certain to happen, and a number in between determines how often it would happen if attempted 100 times. For example, 50% means that it would happen 50 times out of 100 - i.e. half the time such as a coin flip.

## How Much Will I Win?

Fractional odds tell you how much you would win in the top part of the number (the "numerator") if you bet the amount shown on the bottom (the "denominator"). You would also get back the amount you bet (the top part EXCLUDES your bet).

### Example Fractional Odds

Here are some example fractional odds:
• 2/1 - you would win £2 for every £1 that you bet. This means the bookie would return £3 to you for every £1 you bet (£2 profit, plus your £1 bet), if you win.
• 5/2 - you would win £5 for every £2 that you bet. This means the bookie would return £7 to you for every £2 you bet (£5 profit, plus your £2 bet), if you win. This is a profit of £2.50 for every £1 that you bet.
• 1/3 - you would win £1 for every £3 that you bet. This means the bookie would return £4 to you for every £3 you bet (£1 profit, plus your £3 bet), if you win. This is a profit of £0.33 for every £1 that you bet.

Decimal odds tell you how much you would get back for every £1 that you bet, if you win. This number INCLUDES your bet.

### Example Decimal Odds

Here are some example decimal odds:
• 3.0 - you would receive back £3 for every £1 that you bet, so your profit is £2 for every £1 that you bet.
• 3.5 - you would receive back £3.50 for every £1 that you bet, so your profit is £2.50 for every £1 that you bet.
• 1.33 - you would receive back £1.33 for every £1 that you bet, so your profit is £0.33 for every £1 that you bet.

## How to Convert Fractional Odds to Decimal Odds

To convert from fractional to decimal odds: divide the top number by the bottom number, and then add one.

### Example Fractional to Decimal Conversions

Here are some example fractional to decimal conversions:
• 2/1 - divide 2 by 1, then add 1 = (2/1)+1 = 3.0
• 5/2 - divide 5 by 2, then add 1 = (5/2)+1 = 3.5
• 1/3 - divide 1 by 3, then add 1 = (1/3)+1 = 1.33 (this figure is rounded to two decimal places)

## How to Convert Decimal Odds to Fractional Odds

To convert from decimal to fractional odds requires two steps:
1. Step 1 - subtract one, and then use this result as the top number over a bottom number of 1.
2. Step 2 - find the simplest fraction that uses only whole numbers.

### Example Decimal to Fractional Conversions

Here are some example decimal to fractional conversions:
• 3.0 - Step 1: 3.0 - 1 = 2 => 2/1. Step 2: 2/1 already uses only whole number, so no further conversion needed.
• 3.5 - Step 1: 3.5 - 1 = 2.5 => 2.5/1. Step 2: 2.5 is not a whole number, so we need to multiply both the top and the bottom by 2, which gives us odds of 5/2.
• 1.33 - Step 1: 1.33 - 1 = 0.33 => 0.33/1. Step 2: 0.33 is not a whole number, so we need to multiply both the top and the bottom by 3, which gives us odds of 1/3.

## How to Convert Fractional Odds to Probability

To convert from fractional odds to probability: divide the bottom number by the sum of the top and bottom numbers, then multiply by 100. Since bookies try to make a profit, this is really just the implied probability rather than the genuine probability.

### Example Fractional to Probability Conversions

Here are some example fractional to probability conversions:
• 2/1 - divide 1 by 2+1, then times 100 = (1/3) * 100 = 33.3%
• 5/2 - divide 2 by 5+2, then times 100 = (2/7) * 100 = 28.6%
• 1/3 - divide 3 by 1+3, then times 100 = (3/4) * 100 = 75%

## How to Convert Decimal Odds to Probability

To convert from decimal odds to probability: divide one by the decimal odds, then multiply by 100. Since bookies try to make a profit, this is really just the implied probability rather than the genuine probability.

### Example Decimal to Probability Conversions

Here are some example decimal to probability conversions:
• 3.0 - divide 1 by 3, then times 100 = (1/3) * 100 = 33.3%
• 3.5 - divide 1 by 3.5, then times 100 = (1/3.5) * 100 = 28.6%
• 1.33 - divide 1 by 1.33, then times 100 = (1/1.33) * 100 = 75%

## What Odds are Evens?

Odds that are said to be evens are those where there is an equal chance of each outcome. If there are two outcomes (such as winning or not winning) then Evens can be expressed as 1/1 (using Fractional Odds format) or as 2.0 (using Decimal Odds format).

## How to Interpret Odds Ratio

Sometimes Fractional Odds (e.g. 2/1) are written as a ratio (i.e. using a colon ":"). This does not change the meaning, so for example 2/1 is exactly the same as 2:1.

## What is a Value Bet?

A value bet can be made where the true probability of an event is higher than implied by the odds offered by a bookmaker.
Bookies offer high odds on very unlikely events (low probability), and lower odds on more likely events (high probability). Put simply, a value bet is one where the odds offered by a bookie (implied odds) are higher than the odds are in reality (actual odds).

### Coin Flip Example

Let's use an example. When you flip a coin, the probability of heads landing is 50%, and the probability of tails landing is also 50%.
Actual odds are 2.0 in decimal format, which is Evens or 1/1 in fractional format.

If a bookie offered you 3.0 decimal odds on heads (which is 2/1 fractional) that would imply probability of 33%.
Put another way, this foolish bookie thinks that heads will land only 33% of the time.

In this example, the implied odds (3.0 or 2/1) are higher than the actual odds (2.0 or 1/1), so this is a great value bet.
You might not win the first coin flip, or even the second, but over the long run you are guaranteed a profit.

## Which is the Best Bookie in the UK?

This is such a popular question that it now has its own dedicated page, which ranks the best bookies for football.

## Are Higher or Lower Odds Better?

The short answer is that neither is better.
• If you make lots of bets with high odds, you will win a small number of them but each win will be comparatively large.
• If you make lots of bets with low odds, you will win a large number of them but each win will be comparatively small.
Some successful betting strategies will favour higher odds, some successful betting strategies will favour lower odds, and some will use a mix.

## How Do I Win a Bet Every Time?

If you're hoping to win against the bookies every time, the short answer is: "you can't". Bookies don't offer odds on events that are 100% certain. The good news is that you can still make a profit from bookies in the long run if you make value bets.

## What is an Accumulator Bet?

An accumulator is a bet that combines a number of selections into a single bet that pays out only when all of the selections win. Rules on accumulators vary between bookmakers, but usually at least four selections must be made and all selections must be mutually independent.

## Which Bet has the Highest Odds?

The football bet with the highest odds will be an accumulator of lots of very unlikely events. We do not compare accumulator bets since there are too many variations and not all bookmakers will offer odds on each combination.

## Who offers Best Odds Guaranteed for Football?

Best Odds Guaranteed (or BOG for short) is a type of promotion that many bookies offer for racing - usually for horse racing, but often for greyhound racing too. Subject to terms and conditions, it means that winnings are calculated on the best (highest) odds, whether the bet was placed before the race or not.

This guarantee does not apply to football. Instead, bookies constantly monitor and update the odds that the offer before each match (Pre-Match betting) and during the match (Live or In-Play). Any winnings you receive are based on the odds at the time you made the bet.

Bookies do not offer "Best Odds Guaranteed Football", but will still market their odds to appear as enticing as possible. To be sure of getting the best odds, always use an Odds Comparison website - preferably ours!

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