Everybody knows that in betting, bigger odds means bigger returns. So why are the huge majority of bets not placed at the best odds available?

We take a closer look at how odds work in the betting industry and how to ensure you are getting the best prices on offer.

How are betting odds worked out? 

Sportsbooks calculate the probability of all the outcomes of an event. The results are then formed into prices which correlate with the likelihood of each outcome. 

Odds are generally calculated with an 'overround' which give the bookies an edge on the punter. 

Popular selections tend to lead to shorter odds, whereas unpopular selections often see odds widen. Betting odds are similar to any marketplace therefore, where supply and demand dictates prices. 

Why do bookmakers all have different odds for the same event?

Bookmakers tend to start with similar prices for each event. However, each individual sportsbook tends to adjust their own odds depending on the popularity of each selection. 

The opinion of their individual trading teams also plays a role. For instance, Bet365's trading team may often a better price on Manchester United because they're confident that they may lose. This has become increasingly less common, though, due to the emergence of computers, data and algorithms.

Betting exchanges, which are essentially free marketplaces where punters bet against each other, also help form bookmaker prices. 

How much of a difference can using different bookies make?

It can make a huge difference. An average five-fold accumulator could easily differ in 10-15 points of odds depending on which bookie you place it with. For example: 

Bookie A:

Manchester United to beat Wolves - 4/6

Arsenal to beat Crystal Palace - 8/11

Tottenham to beat Newcastle - 6/4

Liverpool to beat Everton - EVS

Chelsea to beat Leicester - 4/7

Five-fold has odds of 21.62/1, so a £10 stake returns £226.20

Bookie B:

Manchester United to beat Wolves - 4/5

Arsenal to beat Crystal Palace - 10/11

Tottenham to beat Newcastle - 13/8

Liverpool to beat Everton - 11/10

Chelsea to beat Leicester - 4/6

Five-fold has odds of 30.57/1, so a £10 stake returns £305.70

So for the same events to occur, Bookie B would pay the punter an extra £79.50 from a £10 stake if all five teams won.

And if you think that's a significant difference, just imagine that kind of extra profit accumulating over the course of a season!

Which websites let me compare odds across bookmakers? 

There are several websites in the UK betting market which let punters compare odds across major sporting events. Here are some of the most popular:

OddsChecker

OddsChecker remains the industry leader for odds comparison. The site was founded back in 1999 and boasts an easy, intuitive interface with an interactive betslip, allowing users to add their selections and showing the sportsbook offering the best prices. 

The site also covers a wide range of markets, ensuring punters are presented with the best possible odds for their selections. 

OddsChecker did recently introduce a paywall earlier this year though, but they still allow a set amount of grids to be viewed for free. 

OddsPortal

While OddsChecker remains the industry leader, OddsPortal also remains a prominent name in the odds comparison market. The site offers a wide variety of European sportsbooks and also shows the overround for each individual sportsbook. 

OddsPortal don't offer direct links to each sportsbooks' bet-slip though, unlike OddsChecker. 

Easy Odds

Easy Odds also offer a strong selection of UK betting markets and has particularly strong coverage of horse racing. 

The site features a system where members are notified when odds on a particular event reach a certain level. Membership also sees a wider range of sportsbooks displayed, though their free selection only allows a small amount to be viewed. 

Easy Odds is probably more time-consuming than the two outlined above, but nevertheless offers a good product for bettors who like to spend time researching before making their selections.

Oddspedia 

A straight-forward user interface also features a host of markets across a wide variety of sports. Oddspedia also allow link users' bet-slips to the sportsbook offering the best price for that individual selection, making for a faster betting experience. 

Interestingly, the site also features reviews for the prominent sportsbooks in the UK, listing the pro's and cons of the service they offer. Leaderboards can also be found across the site, showing which users have made the most profit in a three-month timeframe.

Are there any downsides to using odds comparison sites? 

In all honesty, no. The more advantages you can gain in betting, the better, and odds comparison sites allow punters to see the bigger picture of what's being offered across the markets. 

The only point to consider is if a user continually uses these sites to bet on prices which are clearly human error or arbitrage, this will likely result in restrictions applied to their account as this is considered bad practice.

But, whenever placing a genuine bet, we advise running it through an odds comparison site to ensure you are getting maximum value.