Expected Goals in the Offer Window

In Trefík, from autumn 2023, statistics of expected goals are recorded for matches of the biggest football leagues. It is a post-match statement of how many goals a team should have scored given the number and danger of chances produced by the team's players during the match. It is calculated based on the frequency of how many times the team scores a goal from the situation on the pitch. If the post-match expression of expected goals is, for example, 1.70 : 0.62 for the home team and the match ended with a result of 0:1, then it means that the home team did not take advantage of the game situations that usually lead to at least one goal, and on the contrary, the visitors were able to convert the chance, from which the goal does not fall regularly.

In Trefík, it is possible to monitor the statistics of expected goals in past matches and compare them with the statistics of goals actually scored / conceded. If a team regularly has a higher number of expected goals than the actual number of goals scored in recent games, then they are creating goalscoring chances, but the offensive players are probably not in the shape to take advantage of the chances. In the program, it is therefore possible to work with the shape of offensive players and use it to help you find matches for betting.

To illustrate the program's capabilities, we will create a simple filter for the Offer window:

We will follow the results of the last 3 matches. For this, the "Settings / Maximum how many" item is active = 3. At the same time, the last 3 matches must have taken place in the last 100 days at most: "Settings / How many days to analyze before selected period".
The "Match Stats" section is also active. In it, the statistic "Expected Goals" and the option ".. count G - xG" are selected. This means that the values corresponding to the difference between the actual number of goals and the expected number of goals will be returned. So if a positive value is returned, then the team has scored more goals than the number of chances created in the match. Conversely, with a negative return value, the team scored fewer goals than expected goals. The difference G - xG thus captures how the team's offensive players performed.
In our filter, we will have available the average value of the G - xG difference from the recent 3 matches.
In the Filter / Columns, we activate the items to return the Expected goals, or the difference between the actual and the expected, from the matches of the home team at home and the visiting team away:

In the Offer window, we select the Premier League and matches since 1.8.2023. The result of applying the filter looks like this:

.. the last two colored columns are the actual and expected goal differences for the home team from their last 3 home games and for the away team from their last 3 away games.

Using the value of the difference between actual and expected goals, we can filter the matches in the Filter / Conditions section. This time we'll show you the second option: using a quick filter through the column headers in the Offer window. In the next picture, such a filter is set for away odds values in the range of 2.4 to 3.5 (so we are watching matches that are relatively balanced and the form of offensive players can be a tip on the scales). And at the same time, in the quick filter in the header of the columns, it is set that the difference between actual and expected goals should be 0.5 more goals for the guests than for the home team (it can be said that we are looking for matches where the visiting offensive players have half a goal better shape than domestic players).

.. using this quick filter in the Offer window looks like this:

.. 14 matches have been played so far that meet our conditions, and 5 have ended with a win for the guests. According to the summary for "2" column (defined by the mouse right button menu and the SUM option), when betting on such matches, we would get an appreciation of 106% of the bet amount. However, this is a relatively small number of matches, so we will try to include more competitions in the calculation. And we can see that when betting for home win there would be the profit 21%. But still we need more matches to get from this filter.

At the bottom right, we activate the filter for competitions and define this filter to include the top competitions of England, Italy, Germany and Spain. Applying the filter then turns out like this:

.. we can see the profit summary for each league. We have 55 matches in total from all 4 selected leagues and 6% profit when betting the away team win in all of the returned matches. The best value is for the German Bundesliga when getting the profit if 28%.

When we continue to work in the Offer window, we would probably work with a wider odds limits. And we can add other conditions for searching for matches in the filter (for example, the success of the teams, the ranking of the teams in the table, balances from mutual matches, ...). The purpose of this page was only to show the possibilities of using the "expected goals" value in the Offer window.