Betting on the over under 2.5 and goal index markets in football

Is there still an edge to be found, and how much EV is there vs the odds in the goal index and totals  (over/under) betting markets? We break it down.............

Betting on the over under goal index markets

Betting on the over under 2.5 goals and goal index markets as well as the Asian handicap is the bread and butter of the big football betting syndicates and most professional football bettors. Edges are thin and the very best syndicates are working off just a few %. Total goals betting is the European or Asian equivalent to the money line bets in the NFL over in the US and other big two way markets. 

These over under or Asian handicap markets are controlled by the Asian books and sharp European books. Be aware that betting the unders in the goal index is often a better strategy, in the English Premier league for example, as the bias is on the overs due to the watchers appetite for action often priced in. 

The Covid period was brilliant for betting under 2.5, away wins/draw or any other angles that needed limited action on the soccer field to win the bet. It took the betting markets quite a long time to adjust and catch up while there wasn't enough data to churn out more efficient prices in this uncertain time. 

Finding the edges punting goal index and totals / Over under 2.5 goals markets 

When I was punting football for fun years ago, I always found I had a significant edge on the betting odds offered on the over 2.5 goals markets in certain football matches and certain leagues. La Liga was an absolute gold mine for backing the over 2.5 goals strategy, and buying the the goal spread. There were a number of kamikaze teams such as....

• Atletico
• Betis
• Valencia
• Sevilla
• Villarreal
• Zaragoza
• Sociedad

Matches at this time (~2007-12) involving these teams - especially when they faced each other or the big boys Barca and Real Madrid - were full of goals and the prices were a pickem around 1.90 both sides. The overs were only a smidge shorter when the big 2 were involved. I wouldn't even have put you off an accumulator!

This all slowly changed when managers like Jose Mourinho, Rafa Benitez and Diego Simeone started becoming more prominent on the scene. The 4-4-2 formation turned into 4-3-3 come 4-5-1. Midfields were loaded, and we had the birth of the holding midfielder following on from examples like the Makelele role at Chelsea. Behind the scenes, data was playing more and more of a role in the tactics of certain managers.

What ROI can we expect betting the over under totals in football?

There was a period betting on football over a few years where I built up a large sample hitting around a 65% strike rate on the over 2.5 goals markets, most from matches over in Spain but also being selective and and backing games involving certain teams in the Premier League. The UCL and UEFA CUP were also lucrative. These were the days of the Kanoute / Fabiano strike partnership at Sevilla and David Villa, Juan Mata and David Silva in their prime at Valencia. Not to mention the birth of the Diego Forlan / Sergio Aguero partnership at Atletico.

Goal index betting at that time involving the aforementioned teams was in reality (rather than the probabilities suggested by the odds) approximately closer to 70% in favour of hitting the over 2.5 goals. Unheard of you might imagine. I used to find it fascinating looking at the prices staying the same for such a significant period regardless of numerous 4:3s and similar score lines. Models obviously don't take into account certain type teams playing against certain type teams - this is subjective, and where you can gain an edge by watching. Back then was a period where there was a big inefficiency in the market to exploit. It lasted longer than it should have but was never going to stick for too long.

Let's take a look at the expected value in these goal index markets

These games were being priced up around 1.90 a piece on the over / under lines. Let's work off the 65% strike rate rather than the 70% expected s/r:

1. odds: 1.90 (9/10)
2. win probability: 65 % (0.65)
3. Stake: £100 (example)
4. losing probability: 35% (0.35)

Using the formula for calculating expected value we get...

90 (potential win amount) x 0.65 - 100 (stake) x 0.35 = 23.5% or £23.50. This means we would theoretically be, on average, winning £23.50 per £100 bet.

It makes no difference to the bookmakers that astute bettors could take advantage of this only a minute percentage of the betting population would be able to see that these specific matches severely favoured the over 2.5 rather than the under. The margin, law of averages, volume of rec money and the freedom to move the odds, basically guarantees them a profit in the long run. This is a prime example of how both the bookmaker and the bettor can profit from the same markets and shows restricting winning or shrewd/pro punters is not necessarily the only way to protect their bottom line.

Football right now is again in the midst of a change. A lot of the prices set by the experts are based largely on stats using Poisson and this is how I can find an edge.  Expected goals is the newest metric to predict future performance in football. Logic and subjective variables are the key to successfully finding an edge in these betting markets for me. If you spend thousands of hours watching football some people can begin to project game patterns. 

There are 4 or 5 key variables that I was alluding to above when I mentioned "certain football matches" that I look out for when backing the over 2.5 goals betting markets:

Key variables to beat the goal index markets in football

1. Loose Defense - Key defensive players injured, attacking fullbacks, disorganised set ups and teams who place emphasis on attacking are all factors that lead to gaps at the back. 
2. Three or 4 top strikers on show in the game - an open game is not enough; the over 2.5 goals will not be hit enough times to overcome the odds long term if there are not enough top quality finishers to put away the chances. This is a very significant point and I learned the hard way. Nowadays with usually just 1 out and out striker on show the edges are not as muc
3. Pace in attack - For plenty of clear cut chances/ one on ones in a game, pace in behind is key. Pace on the wings and in attack also stretches the game and opens it up. 
4. Only 1 defensive midfielder - There's nothing worse to stifle a game than 2 teams playing with 2 defensive central midfielders. With the likes of Klopp and Guardiola now making teams focus on more possession based attacking football, it is better for the over 2.5 goals backers. This is probably the most overlooked factor and the first thing I look for - How many defensive Makelele or Kante or Fabinho type players are flooding the midfield.

Summary of the goal index football markets

The general rule in goal index betting is the more defensive minded the football managers are, the more boring the game is likely to be - soccer teams tend to be an imitation of the managers personality or philosophy. If Jose Mourinho takes over a team, expect dour football, for example. 

We can now use shot quality in the form of Expected Goals (xG) to try and gain an extra edge. Different models quantify this differently so there's plenty of room for error. Refer to what I said about strikers.

 Brighton in 2020/21 had a high average rating in expected goals but was it deserved? What I mean by that is would a large sample see them reaching this xG average, or are they just creating a lot of good scoring opportunities but don't have the strikers of good enough quality to finish them? (refer to point no.2)

All these and more are factors I look out for to gain an edge on over 2.5 goals betting odds and you should keep them in mind when sizing up your own bets on the overs.