What is Implied Probability in Betting?

If you’re new to betting in all its guises, including online, you may not know that there is considerable math behind the magic. In fact, experienced bettors are adept at using something known as implied probability to determine whether a wager offers value.

In the sports betting world, bettors can convert decimal, fractional and American odds formats into implied probabilities to understand how likely a sportsbook believes an outcome will be.

The term implied probability is also known as implied odds in the poker scene. In fact, the term ‘implied odds’ is one of the most important terms in the poker dictionary, as it can improve a player’s long-term results. Poker players can use this calculation to determine how much they can expect to win if they hit the cards they need to win on the turn or river.

Below, we’ll provide a couple of examples using implied probability for both sports betting and Texas Hold’em poker to demonstrate the versatility of this metric in finding value betting opportunities.

Understanding implied probability in sports betting

Let’s say you wanted to bet on the likelihood of an English Premier League football match between Manchester City and Arsenal finishing with over 2.5 goals. A sportsbook is offering odds of 1.80 in decimal format (4/5 in fractional and -125 in American).

To determine what the sportsbook’s traders believe to be the implied probability of this happening, you need to do the following calculation:

(1/1.80) x 100 = 55.55%

Ultimately, the sportsbook believes there’s a 55.55% chance of this match ending with three or more goals. When you consider their latest match-up resulted in a heavy defeat for the Gunners, you may feel the likelihood is greater than this. Therefore, it’s a good price to take as you’re getting value odds based on your own implied probability. Let’s say, you think there’s a 65% chance of it occurring. This gives you a 9.45% edge over the sportsbook.

Your success as a sports bettor will ultimately rely heavily on your interpretation of pre-game data and pre-game implied probabilities being more accurate than the in-house traders of your chosen sportsbooks.

Implied probabilities can also be used to find sportsbooks offering the smallest margins, also known as vigorish. Imagine if one of the daily football tips was priced as:

Manchester City – 1.40
Draw – 5.00
Burnley – 7.50

Man City (71.42%) + Draw (20%) + Burnley (13.33%) = 104.75%

That’s a house edge or vigorish of 4.75% above 100% if all implied probabilities were fair and even.

Ultimately, you can use implied probability to find odds with the lowest available vigorish, to get as close to fair value for your betting odds as possible.

Mastering implied odds in poker

Implied odds differ slightly to the term pot odds in poker. Pot odds focus squarely on the likelihood of a drawing hand winning. Think of implied odds as an extension to this basic calculation. It tells you how much you’re likely to win if your drawing hand wins. If you feel you’re unlikely to extract more money from opponents betting on future streets, there’s next to no implied odds available.

Let’s say that your hole cards are 9-10 unsuited. The flop comes J-A-8. This is a great spot for implied odds, as you have an open-ended straight draw. You only need a 7 or a Queen to make a straight. If your opponent bets first, you’re therefore getting good, implied odds to call. If you happen to make your straight, it’s likely you’ll be able to take more money from your opponent on the turn or river. That’s because they may not anticipate your straight and be blinded by their pair of Aces.

If you have hole cards of 7-K unsuited and the flop is 10-J-Q, you still have an open-ended straight draw, so why are the implied odds much worse? Well, let’s say an Ace appears on the turn. This becomes a scary card for an opponent who may have had just top pair (QQ) on the flop. Straight possibilities are also more obvious to opponents, so a strong bet on the turn could cause them to shut down and fold. The easier it is to disguise your drawing hand, the greater your implied odds will be.

It’s easy to see how implied probability can be a useful weapon in your betting arsenal to improve your value betting. It helps to avoid those newbie errors which can cause your bankroll to ebb away long term.