How are betting odds calculated?

In 2015, the total Gross Gambling Yield for the gambling industry in Great Britain was worth a staggering £12.6 billion. The rise of online gambling has helped make betting a national pastime, with the most popular types of gambling using various odds including the lotto and scratch cards, casino gambling such as poker, blackjack and fruit machines, as well as sports betting and racing.

All types of gambling differ greatly. However, they all share a common thread. And that is that despite the incredible figures involved, very few people outside the industry know about how the betting odds are calculated.

betting odds

How are different types of betting odds calculated?

Lotto betting

Lotteries represent a huge part of the betting industry in the UK. Last year, National Lottery sales hit a record £7.6 billion, with more players buying tickets via smartphones more regularly.

Contributing to this rise in popularity is the increasing availability of foreign lottos on online sites in the UK. For example, UK residents can now partake in Irish lotto betting online without having to take a flight to Ireland, and as we’ll discuss shortly, that method may help them improve their odds.

Of course, lotto betting generally involves a very small amount money gambled, and potentially a very large payoff. However, the chances of winning the jackpot are slim to none, as WikiHow explains in this handy infographic.

This explanation is simplified, and in most lottos there is a powerball, which makes the chances of winning the jackpot even smaller. So, if we use this theory to explain the odds of winning the UK National Lotto, the odds of winning are approximately 1 in 14 million. With six numbers between 1 and 49 to choose, the equation to work out odds is 49!/(6!*(49-6)!). A painful equation to type and read. However, and this perhaps explains the rise of online lotto betting, the odds of winning the Irish Lotto is 1 in 10,737,573.

Sports gambling

Sports betting makes up for the bulk of gambling in the UK, with a whole host of bookies focusing on horse and greyhound racing, football and boxing. At current estimations, the global football betting industry is worth between $700 billion and $1 trillion a year.

Of course, sports gambling differs significantly from lotto betting. The odds of an outcome at a sporting event is significantly more likely to happen than a jackpot win. According to Ladbrokes, rather than calculating odds with true probabilities, bookmakers adjust them slightly in their favour, which is hardly surprising. For them, it’s about finding the right balance between making a profit and ripping off the customers.

Looking at Premier League football, Soccer Widow worked out that on average 24.46% of all games were drawn, 27.35% ended in an away win and 48.16% were won by the home team. Online bookmakers consider these longer term odds when calculating the likelihood of results during specific games.

However, the growing demand for sports bets means you can now bet during match play, on anything from the number of corners in a half, to the exact time of a substitution, to whether the reserve goalkeeper eats a pie – seriously.

Casino odds

Despite being dwarfed by the success of high street bookmakers, and the fact that the number of betting shops, arcades and bingo premises in the UK are decreasing, casinos in the UK are still big business. In London alone there are more than 20 licensed casinos.

Of course, odds vary depending on the game and how skilled or experienced a player is. Casinos are businesses and their end goal is to take gamblers’ money, but players can come out on top if they quit while they are ahead. However, the old adage ‘the house always wins’ has a degree of truth in it. Casinos have a built in advantage called the house edge which is usually around 5% This means that, on average, for every £1 a punter spends, they will receive 95p back and the house will keep 5p.

Vegas Click state that “the casino doesn’t have to destroy you with terrible odds — they give you an almost even game and make just a few percent on each bet on average.” That way, the odds will always work against you eventually.