Betting odds explained: How do you read them & when do they change?

What are betting odds?

Betting odds are a way of displaying the potential profit you can make when placing a bet.

They are the ‘price’ offered by sports betting sites and other bookmakers to bettors.

Bookmakers offer ‘short’ odds when they believe the outcome is likely to occur and your bet is more likely to win. This bet is less ‘risky’, hence the smaller payouts.

When ‘longer’ odds are offered, that means the bookmaker believes the outcome is less likely to happen. Larger payouts must therefore be offered to players to entice them to place bets on these markets.

How are sports betting odds calculated?

Sports betting odds are calculated based on several factors:

• The probability of an event occurring
• The vigorish (‘vig’)
• Market sentiment/trends

How do bookmakers calculate event probabilities?

Bookmakers conduct in-depth statistical analysis to calculate the probability of a specific outcome occurring in a sports event.

These models include numerous variables such as past team and player performance, opposition strength, tournament progression and even referee/umpire performances, travel distance or weather.

**To offer live betting odds, betting sites must also include live event data in their statistical models because each event in a match (plus time decay in some markets) will impact the probability of many other outcomes.

What is the vigorish in sports betting?

The vigorish (or ‘vig’) is a form of insurance baked into sports betting odds that ensures the bookmaker makes a profit on all possible outcomes.

For example, a coin toss has two possible outcomes - heads or tails. There is a 50% chance of landing on heads and a 50% chance of landing on tails.

However, a bookmaker is likely to offer you odds on heads or tails with implied probabilities higher than 50%, meaning that the sum of the percentage chances of all possible outcomes is more than 100%.

The sum of these percentages is called the overround (o), and the vig (v) can be calculated using the following formula:

v= (o-1/o)

Betting sites will add a higher vig to markets where they are less sure of the outcome, for example if there are many different possible outcomes or the event is further away in time.

Competition from other bookmakers can help to drive vig down as each tries to offer more attractive odds than the other.

How do market trends affect betting odds?

Betting activity can significantly impact betting odds.

For example, if a betting site opens betting on an event and they realise that every single player is backing the favorite to win, that implies that they should have priced the favorite shorter and they will adjust the odds accordingly.

Ryan Davis Site Manager

Whether these bets are being placed on ‘feel’ or factual data is irrelevant.

The only thing that matters here is the amount of money being wagered on each outcome.

Market trends and sentiments can be particularly impactful in in-play markets (and especially on betting sites with live streaming) as people react to live match events.

For example, a batter playing and missing several balls in quick succession in a cricket match may result in more bets on the bowling team to win or on the batter to score under a certain number of runs.

In this situation, cricket betting sites would shorten the odds on the bowling team.

Types of betting odds & how to read them

There are several different types of betting odds. The most common odds format is decimal odds which is used in many countries, including the UAE.

Moneyline and fractional odds are also popular but generally only in the United States and the United Kingdom.

Decimal odds

Decimal odds show how much money you will end up with for a winning $1 bet.

For example, if you place a $1 bet at decimal odds of 1.50, your total payout will be $1.50 (50c profit, plus your original stake back).

Hong Kong odds

Hong Kong odds are very similar to regular decimal odds - they just don’t include your original stake.

For example, decimal odds of 1.50 would be displayed as 0.50 in Hong Kong odds format.

A winning $1 bet at Hong Kong odds of 0.50 would net you a total payout of $1.50.

Malaysian odds

Malaysian odds are different type of decimal odds where positive decimal numbers represent odds-on selections, negative decimal numbers represent underdogs/odds-against and odds of exactly 0 mean even money (50/50 - 2.0 in standard decimal odds).

For example, a winning $1 bet at Malay odds of 0.5 would make a profit of 50c for a total payout of $1.50.

A winning $1 bet at Malay odds of -0.5 would make a profit of $2 for a total payout of $3.

Moneyline odds

Moneyline odds work from a baseline of $100 stakes with favorites and underdogs indicated using negative and positive numbers respectively.

The negative odds for the favorite show how much you would need to bet in order to win $100.

The positive number denoting the underdog shows what you would win with a $100 bet on that selection.

For example, if you place a $150 bet on the favorite at -150, your profit will be $100 and your total payout will be $250.

If you bet $100 on the underdog at +150, your profit will be $150 and your total payout will be $250.

Indonesian odds

Indonesian odds work on the same premise as moneyline (American) odds, with the difference being that Indonesian odds are expressed as a decimal (moneyline odds divided by 100).

For example, if you place a $150 bet on the favorite at -1.5, your profit will be $100 and your total payout will be $250.

If you bet $100 on the underdog at +1.5, your profit will be $150 and your total payout will be $250.

Quoted odds of 1.0 therefore represent even money (50/50) bets in Indonesian format.

Fractional odds

Fractional odds show how much profit you will make relative to your stake. This format is mostly used in the UK and Ireland.

The numerator (top/first number) of the fraction shows how much profit you will make based on the stake (bottom/second number).

For example, if you place a $1 bet at fractional odds of 1/2, a winning bet will return 50c profit and a total payout of $1.50.

If you place a $1 bet at odds of 2/1, a winning bet will return $2 profit for a total payout of $3.

Even money (50/50) bets are shown as 1/1 (some betting sites prefer to display this as EVS).

What does SP mean in betting odds?

SP is short for starting price and is mostly used in horse racing.

If you place a bet at SP, it is struck at whatever the odds on that selection are when the race (or other event) starts.

The advantage of placing a bet at SP is that you might secure much better value odds if the price subsequently comes in based on market sentiment or other information that favors your pick.

On the other hand, you risk taking much worse value odds if your pick becomes less likely to win by the start of the race.

Which betting odds format is best?

There is no ‘best’ betting odds format - they all display the same information in different ways.

Ryan Davis Site Manager

I personally prefer to use decimal format, but that is purely because that is what I am most used to. If I had done a lot of betting in the USA, I'm sure the moneyline format would feel more intuitive to me.

Many betting sites give you the option to display odds in several different formats. For example, at 1xBet you can display odds in any of the six of the formats explained above.

Sports betting odds FAQs