Another Betting School article. This time one I originally wrote in April 2013. This one looks at goal times and the impact of an early goal.
The early goal catches the worm
I was struggling through Osasuna v Atletico Madrid and trying to find things to do other than watch the match when a goal was scored. The goal was scored in the 35th minute and I wondered what the likelihood of more goals was. Before the goal I had looked at the under 2.5 goal price and it was around 1.55 so goals certainly weren’t expected in large numbers. Obviously this goal made over 2.5 more likely but was there a way of working out how much more likely?
I decided to do some research into it and that is what I am going the share with you. I have used the betexplorer.com site as they provide odds for matches and the goal times if you click on the link to any match. I always like to look at the major leagues so I have used the Premier League, La Primera in Spain , Serie A in Italy, the Bundesliga in Germany and the French Ligue 1. For all these leagues I have used data from this season. I also added the Championship as there is no doubt more interest in English leagues amongst the readership. This season is heading towards the finish line but there is a lot of football still played in the summer so I have used the MLS in America and the J-League in Japan. For these two leagues I have used data from last season which ran throughout 2012.
The main market to look at in all this is the over/under 2.5 goal market as this is the classic goal line. Let’s see on average how many games from each of these leagues are over/under 2.5 goals and how many matches are included for each league in this study.
| Total | Over 2.5 | Under 2.5 | ||||
| League | Season | Games | Games | % | Games | % |
| Eng Champ | 2012-13 | 453 | 238 | 53% | 215 | 47% |
| Eng Prem | 2012-13 | 296 | 168 | 57% | 128 | 43% |
| French Ligue 1 | 2012-13 | 290 | 131 | 45% | 159 | 55% |
| German Bundesliga | 2012-13 | 234 | 124 | 53% | 110 | 47% |
| Italy Serie A | 2012-13 | 288 | 141 | 49% | 147 | 51% |
| Japan J-League | 2012 | 306 | 158 | 52% | 148 | 48% |
| Spain La Primera | 2012-13 | 280 | 148 | 53% | 132 | 47% |
| USA MLS | 2012 | 323 | 165 | 51% | 158 | 49% |
| Total | 2470 | 1273 | 52% | 1197 | 48% | |
Table 1. Number of matches for each league included in study and counts and percentages of games which were over or under 2.5 goals
Looking at the table the first thing that stands out is the number of games in the Premier League that have been over 2.5 goals. I have no idea why, but would presume this is a blip as it is way ahead of all the other leagues. If you remove the Premier League and France from the data then all the rest are pretty consistent lying between 49% and 53%. The average is 52% across all these leagues and I always think this demonstrates why over/under 2.5 goals works so well in betting as the line is so close to 50%. You can see prices for the coming matches on the Bet365 website.
We want to look at the time of the first goal and see how that impacts on the over/under market; so let’s first look at the times of the first goal across the leagues to get an idea of when it occurs. The results are shown in table 2.
| League | 0-10 | 11-20 | 21-30 | 31-40 | 41-50 | 51-60 | 61+ | 0-0 |
| Eng Champ | 18% | 20% | 14% | 11% | 10% | 8% | 13% | 6% |
| Eng Prem | 22% | 19% | 11% | 13% | 8% | 7% | 11% | 9% |
| French Ligue 1 | 16% | 19% | 12% | 14% | 10% | 8% | 14% | 8% |
| German Bundesliga | 25% | 14% | 17% | 14% | 12% | 4% | 7% | 8% |
| Italy Serie A | 20% | 17% | 13% | 10% | 8% | 9% | 15% | 8% |
| Japan J-League | 19% | 19% | 11% | 11% | 12% | 7% | 14% | 8% |
| Spain La Primera | 22% | 19% | 17% | 9% | 7% | 6% | 13% | 6% |
| USA MLS | 21% | 21% | 11% | 6% | 10% | 7% | 16% | 7% |
| Total | 20% | 19% | 13% | 11% | 10% | 7% | 13% | 7% |
Table 2. Time of the first goal in matches, grouped in 10 minute brackets, as a percentage of the total matches
I was surprised by how many matches feature an early goal. Across all leagues on average 1 in 5 matches has a goal before the 10th minute. It feels like I never watch these matches, that’s for sure. The Bundesliga produces some odd figures having the highest percentage in the 0-10 bracket and the lowest in 11-20 but they probably average out like the others if you looked at 0-20 as a whole. If we know there are quite a lot of early goals let’s look at the 4 brackets from 0-40 minutes and see what impact the goal has on the over 2.5 goal expectancy. The results are shown in table 3.
| All | 0-10 | 11-20 | 21-30 | 31-40 | ||||||
| League | O | U | O | U | O | U | O | U | O | U |
| Eng Champ | 53% | 47% | 75% | 25% | 71% | 29% | 75% | 25% | 55% | 45% |
| Eng Prem | 57% | 43% | 83% | 17% | 75% | 25% | 58% | 42% | 57% | 43% |
| French Ligue 1 | 45% | 55% | 67% | 33% | 65% | 35% | 57% | 43% | 51% | 49% |
| Ger’ Bundesliga | 53% | 47% | 69% | 31% | 67% | 33% | 60% | 40% | 63% | 38% |
| Italy Serie A | 49% | 51% | 71% | 29% | 67% | 33% | 70% | 30% | 43% | 57% |
| Japan J-League | 52% | 48% | 90% | 10% | 72% | 28% | 62% | 38% | 46% | 54% |
| Spain La Primera | 53% | 47% | 74% | 26% | 66% | 34% | 69% | 31% | 42% | 58% |
| USA MLS | 51% | 49% | 71% | 29% | 72% | 28% | 68% | 32% | 45% | 55% |
| Total | 52% | 48% | 75% | 25% | 70% | 30% | 66% | 34% | 51% | 49% |
Table 3. Breakdown of matches which have over or under 2.5 goals based on the time the goal was scored. Goals are grouped in 10 minute brackets and ‘All’ is included to allow comparison.
Very interesting and some possible angles that could be exploited. It is no surprise that if there is a goal in the first 10 minutes of a match the likelihood of the game going over 2.5 goals is greatly increased. If we look at all matches the average is that it happens in 75% of matches, so if you got to the 10th minute of a match and a goal had been scored then you would want to be backing over 2.5 goals at a price better than 1.33 to get some value. I calculated that by converting 75% to decimal odds (1/0.75).
My view is that by using the odds required we can get a much better picture of the jump that occurs in the 10 minute brackets and this is shown in table 4.
| Percentage | Equivalent Odds | |||
| Minute | Over | Under | Over | Under |
| 0-10 | 75% | 25% | 1.33 | 4.01 |
| 11-20 | 70% | 30% | 1.43 | 3.31 |
| 21-30 | 66% | 34% | 1.52 | 2.93 |
| 31-40 | 51% | 49% | 1.96 | 2.05 |
| 41-50 | 52% | 48% | 1.91 | 2.1 |
| 51-60 | 38% | 62% | 2.64 | 1.61 |
Table 4. Equivalent odds based on the percentages of matches that go over or under 2.5 goals based on the time bracket of the first goal
The table above shows very well the big drops in the percentage of games that go over 2.5 goals if a goal is not scored before the 30th minute, and then again after the 50th minute. I have charted the results as well in figure 1 to allow further analysis.
Figure 1. Line chart showing percentage of games over 2.5 goals based on time of 1st goal.
I wanted to visualise this data to see if it is easier to see the change, as from the table it looks to be steady but then dips drastically. In figure 1, I grouped the minutes in pairs (1-2, 3-4 etc) to lessen the spikes in the chart. The chart shows a steady gradual decline to just before the 30th minute and then there does seem to be a drop. The bigger and more clear drop is the next one just after half time and therefore the chances of over 2.5 occurring drops steeply after half time.
We have some basic facts but then there are some factors we should probably consider, such as if the team that scores first is the home team or the away team. In table 5, I have produced the same figures we have in table 3 but broken down by if the home team or the away team scored first.
| All | 0-10 | 11-20 | 21-30 | 31-40 | |||||||
| League | 1st | O | U | O | U | O | U | O | U | O | U |
| Eng Champ | Hm | 60% | 40% | 86% | 14% | 78% | 22% | 64% | 36% | 52% | 48% |
| Aw | 52% | 48% | 63% | 37% | 63% | 37% | 82% | 18% | 58% | 42% | |
| Eng Prem | Hm | 67% | 33% | 91% | 9% | 79% | 21% | 67% | 33% | 50% | 50% |
| Aw | 58% | 42% | 75% | 25% | 72% | 28% | 50% | 50% | 63% | 37% | |
| French Ligue 1 | Hm | 54% | 46% | 54% | 46% | 68% | 32% | 77% | 23% | 53% | 47% |
| Aw | 45% | 55% | 81% | 19% | 63% | 38% | 45% | 55% | 50% | 50% | |
| German Bundesliga | Hm | 60% | 40% | 74% | 26% | 67% | 33% | 53% | 47% | 53% | 47% |
| Aw | 55% | 45% | 58% | 42% | 67% | 33% | 64% | 36% | 71% | 29% | |
| Italy Serie A | Hm | 65% | 35% | 76% | 24% | 73% | 27% | 79% | 21% | 67% | 33% |
| Aw | 42% | 58% | 64% | 36% | 61% | 39% | 61% | 39% | 28% | 72% | |
| Japan J-League | Hm | 54% | 46% | 84% | 16% | 74% | 26% | 77% | 23% | 29% | 71% |
| Aw | 57% | 43% | 96% | 4% | 70% | 30% | 52% | 48% | 57% | 43% | |
| Spain La Primera | Hm | 63% | 37% | 83% | 17% | 81% | 19% | 85% | 15% | 36% | 64% |
| Aw | 51% | 49% | 65% | 35% | 50% | 50% | 57% | 43% | 50% | 50% | |
| USA MLS | Hm | 60% | 40% | 81% | 19% | 77% | 23% | 69% | 31% | 50% | 50% |
| Aw | 50% | 50% | 61% | 39% | 66% | 34% | 67% | 33% | 42% | 58% | |
| Total | Hm | 60% | 40% | 80% | 20% | 75% | 25% | 71% | 29% | 49% | 51% |
| Aw | 51% | 49% | 70% | 30% | 64% | 36% | 62% | 38% | 53% | 47% | |
Table 5. Breakdown of matches which have over or under 2.5 goals based on the time the goal was scored and by which team. Goals are grouped in 10 minute brackets and ‘All’ is included to allow comparison.
The table is a little busy but if you start with the total line you immediately get a feel of what happens. If the home team score first then the likelihood of there being more goals is much more likely.
If the home team scores first before the 10th minute then in 8/10 matches the game goes on to have over 2.5 goals. Compare this to the away team scoring before the 10th minute and this drops to 7/10. Thinking of the equivalent decimal odds it would mean you would need on average odds of over 1.42 (1/0.7) on over 2.5 goals if the away team scored but just 1.25 (1/0.8) if the home team scores; and that is a big difference. Even if the home team scores between the 11th and 20th minutes there is still a 75% chance of over 2.5 goals.
I just want to have one more dig into this data and will stick with the home teams but group them in terms of odds. I have made 4 brackets for the home team price which is less than 1.5, 1.5 to 1.99, 2-2.99, 3-3.99 and 4+.
| 0-10 | 11-20 | 21-30 | 31-40 | |||||
| Odds | O | U | O | U | O | U | O | U |
| <1.5 | 95% | 5% | 88% | 12% | 88% | 13% | 100% | 0% |
| 1.5-1.99 | 81% | 19% | 75% | 25% | 68% | 32% | 47% | 53% |
| 2.0-2.99 | 77% | 23% | 73% | 27% | 70% | 30% | 53% | 47% |
| 3.0-3.99 | 74% | 26% | 69% | 31% | 67% | 33% | 38% | 62% |
| 4+ | 76% | 24% | 79% | 21% | 75% | 25% | 21% | 79% |
| Total | 80% | 20% | 75% | 25% | 71% | 29% | 49% | 51% |
Table 6. Breakdown of matches which have over or under 2.5 goals when the home team scores first based on time the goal was scored and the pre-match odds of home team.
I grouped all the matches together to give a bigger sample size. Again there is the clear drop off as you pass the 30th minute and this is even more pronounced when the away team has a bigger price.
It is interesting in this group that in the matches where the home team was priced below 1.5 and they scored anytime before the 40th minute then over 90% (64 out of the 70 matches) were over 2.5 goals. This is a small sample but there looks likely to be a fair few goals even if the home favourite takes a while to get going.
Hopefully this will give you some added insight when a goal goes in. Thinking about the time that is was scored and by which team should enable you to make a decent decision on whether to back over or under 2.5 goals.