The Euro Club Index (ECI) is a ranking of the football teams in the highest division of all European countries, that shows their relative playing strengths at a given point in time, and the development of playing strengths in time. The ECI makes it possible to calculate the probabilities of different match results (win, draw, loss) for football matches in the near future.
The ECI-value of a team represents the expected level of sporting success. The ECI-values are derived from historical and actual sporting results: in league matches, in national cup matches and in UEFA Champions League, UEFA Europa League and UEFA Super Cup matches.
The ECI-values are calculated, based on all relevant match results from several recent seasons, using scientific statistical methods. The impact of more recent matches on the ECI-value is higher than that of older matches. The ECI is constructed in such a way, that its predictive force is maximized.
Weekly publishing of the ECI-ranking for the teams in the highest division of all European countries reflects the actual playing strengths in Europe. Biannual reports show the development of playing strengths for teams and countries.
For each country a national ranking is published weekly, as a subset of the ECI. The impact of the match results of the previous week on the ECI-values is shown. Biannual reports show the development of playing strengths of the teams.
The actual ECI-values will be used to give the probabilities of the different match results for upcoming matches. This is interesting for the general public, for the media, for the clubs and for betting purposes.
Start values of ECI
Based on the sporting results of three consecutive seasons, the relative playing strengths are calculated of all relevant teams within each country on the start date (i.e. July 1, 2007). Also the relative strengths are calculated of the teams that have represented their country in the UEFA Champions League, UEFA Europa League and UEFA Super Cup. The result is an ECI-value for all relevant teams on the start date.
Match result probabilities
The result of a football match depends on the playing strength of the teams, the home advantage and the match performance of the teams. The playing strength is given by the ECI-values. The match performance will vary according to a normal distribution. This way it is possible to calculate the probabilities of the different match results (win, draw, loss).
Example: if the ECI of the home team is 500 points higher than the ECI of the away team, the probability of a home win is 66% (3 in the graph).
Actual values of ECI
After the start date, the result of every match will change the ECI-value of both teams that played. The estimated outcome of the match (a real number between -1 and 1) is compared with the real outcome of the match (1 for home win, 0 for draw, -1 for away win). The difference between the two numbers is multiplied by a constant, the k-factor. The result is added to the home team ECI and subtracted from the away team ECI.
Example: a match between team X with ECIX = 2,400 and team Y with ECIY = 1,900 has an expected result of: 1 x 66% + 0 x 19% - 1 x 15% = 0.51
The table shows the changes in ECI based on the match result (in this example the k-factor = 35)
|Home team win
||35 x (1 – 0.51) = 17
||2,400 + 17 = 2,417
||1,900 – 17 = 1,883
||35 x (0 – 0.51) = -18
||2,400 – 18 = 2,382
||1,900 + 18 = 1,918
|Away team win
||35 x (-1 – 0.51) = -53
||2,400 – 53 = 2,347
||1,900 + 53 = 1,953
The updated ECI-values reflect the changes in playing strength. The team that performs better than expected will go up on the ECI, the team that performs worse than expected will go down on the ECI.
After each round in a League, the odds for the championship of the League are calculated, based on the actual standing and the match result probabilities for all remaining matches. For each team the expected number of points at the end of the competition is calculated, with the corresponding bandwidth. Also for each team the chance to become champion is calculated.
Sometimes it happens that a team with a smaller number of expected points has a higher chance of becoming champion, this is due to the bandwidth in the remaining schedule. For example if team A has an expected number of points of 75 +/- 2 and team B has 74 +/- 4 it is possible for team B to have higher championship chances.