Soccer bettors are increasingly looking for more profitable markets than 1X2, for which a lack of goals or a late equaliser can deny even the best judgments a winning bet. A straightforward way to try and beat the bookies on the soccer front is with the Over/Under goals markets. This article offers a simple step-by-step guide on how to calculate probabilities for the expected number of goals in a match and convert them into odds, so that you know what to bet on and what to avoid.
Step 1: Find the average number of goals per game
In comparison to most sports, scoring in soccer is a less frequent event and it is certainly not uncommon for a match to feature no goals whatsoever. This means that when it comes to betting, bookmakers study the average number of goals scored per match for the two teams involved in the fixture in question when assessing the odds for the Over/Under markets.
If over 2.5 goals for a Premier League match is available with Pinnacle at 1.925 and another bookmaker is offering the same bet at 1.800, you know that you are better off at Pinnacle. However, how you do assess if it is worthwhile betting your money on this market to begin with?
Suitably, the best place to start is with the same method as the bookmakers – by finding the average number of goals per game for the two teams involved in the match you are interested in betting on.
This is generally an easy figure to research online. To provide some detail, here are the average goals per game for several major soccer leagues and competitions during the last three seasons:
|UEFA Champions League||2.93||3.21||3.04|
|English Premier League||2.82||2.68||2.80|
|UEFA Europa League||2.76||2.71||2.76|
|2018 FIFA World Cup||2.64||–||–|
As the above table highlights, major soccer leagues and competitions have predominantly averaged between 2.5 and 3 goals per game in recent years, although any given league or competition should be considered on an individual basis. For instance, last season the Hong Kong First Division averaged a massive 4.12 goals per game, whereas the El Salvador Premiera Division only mustered a mere 1.83.
Step 2: Calculate the probabilities
The random nature of goal scoring enables statistics to follow a poisson distribution as a simple predictive model for Over/Under betting. It is important to establish what that means in practice.
In his book Taking Chances, John Haigh drafted a table that calculates the probabilities of a team scoring none, one, two, three or four or more goals based on their average number of goals per game:
|Average number of goals||0||1||2||3||4 or more|
For a match where the home team has averaged 1.2 goals per game and the away side have averaged 0.8, it is easy to determine the probability for under 2.5 goals occuring by using the above table.
Firstly, determine the correct scores that will lead to a winning under 2.5 goals bet (0-0, 1-0, 0-1, 1-1, 2-0, and 0-2). You can then find the respective probabilities for each team from the above table and mutiply them together to calculate the probability for each scoreline:
|Exact score||Probability of home team|
to score the indicated number
|Probability of away team|
to score the indicated number
of exact score
|0-0||30%||45%||30% x 45% = 13.5%|
|1-0||36%||45%||36% x 45% = 16.2%|
|0-1||30%||36%||30% x 36% = 10.8%|
|1-1||36%||36%||36% x 36% = 12.96%|
|2-0||22%||45%||22% x 45% = 9.9%|
|0-2||30%||14%||30% x 14% = 4.2%|
|Total under 2.5 goals probability:||67.56%|
Since we know the individual probabilities of each potential score that can lead to under 2.5 goals occurring, we can add them together to get the overall probability of the match ending in under 2.5 goals and, therefore, a winning under 2.5 goals bet.
In this example, that would be:
13.5% + 16.2% + 10.8% + 12.96% + 9.9% + 4.2% = 67.5%
Step 3: Determine what odds are worth betting on
Once you have established the statistical probability of the match to end in less than 2.5 goals, you are then in a position to determine which odds you should accept.
To convert probability into decimal odds, you use the following simple formula:
Decimal odds = 100 / probability
In the above example, a 67.56% possibility corresponds to an equation of 100 / 67.56, which equates to decimal odds of 1.48.
This means that you should only bet on under 2.5 goals for a match if you find a bookmaker offering odds of higher than 1.48.
Naturally, this approach does not guarantee a winning bet. However, it does provide an easy to apply betting strategy with positive expected value that should secure profits over a long span of time when aggregrating your long-term losses and profits.
Do this research ahead of any match you are considering placing an Over/Under goals bet on and you can sit back and enjoy the action, knowing that you have put yourself in the best possible position to win your bet.