Historic Rating Correction Required

A very important question for a rating system like the Football Club Elo Ratings is how to choose the initial values. This is a smaller problem when continuous data for more than 50 years is available, but it becomes a big issue if your ratings start ... (read more)

Average Elo of Top Leagues

Which league is the best in Europe? While it is certainly possible to group leagues into better and less good leagues, it is hard to find a universally recognised scale. ... (read more)

Adaptive Poisson parameters and result histogram

To calculate the probability of football results, I have so far used the Poisson distribution for the number of home and away goals in a match. Depending on the difference in Elo points between two teams, the average number of goals scored and conced ... (read more)

The European Cup winners and how good they really were

The Champions' League and in former times the European Cup has been created to find the champion of the champions, or the best team in Europe. How well does this competition achieve that? The following table shows every European Cup winner since 1956 ... (read more)

Home Field Advantage per Country

This article spotlights the development of home field advantage in European football. The pure existence of home field advantage already is a mystery, it can be observed in many sports and also in football. We have seen that home advantage has been m ... (read more)

Adaptive Home Field Advantage

This article describes a new method of determining the home field advantage in club football. As opposed to the static method that has been applied so far, from now on home field advantage will adapt to results every day and will be different in ever ... (read more)

Created: 23 Mar 2013 - Modified: 24 Mar 2013

New Formula for 2-Leg-Games

The current method of calculating two-leg games takes into account the aggregate result, increases its weighting and subtracts the result of the first leg. Please see ... (read more)

Created: 23 Mar 2013 - Modified: 20 Jan 2013

Server migration and more changes

Until now, to update Clubelo, I calculated the rankings on my computer and uploaded them via FTP. That meant that if I was on holiday or otherwise busy, updates were delayed. That is why I spent some time migrating and automating the whole site on a ... (read more)

Created: 23 Mar 2013 - Modified: 20 Jan 2013

Improving the prediction model

In the last article, we compared the predictions of the Elo model with the actual average results for each percentile and we found out that it is quite well predicting the outcome of future matches but there is still room for improvement. This articl ... (read more)

Created: 23 Mar 2013 - Modified: 3 Apr 2013

How accurate is the Elo system and its predictions

Many sites offer predictions for football matches, very few of them actually review and publish analyses of their predictions. Having over 260000 football matches in the database, I wanted to see how my system stands the reality check. Does a team re ... (read more)

Created: 23 Mar 2013 - Modified: 14 Jul 2012

The mysterious decline of home advantage

This article shows that home advantage in European club football is massively decreasing since the seventies.
When I started this site, the oldest results that were included in the database were from 1993. I used them mainly for calibration and to ha ... (read more)

Created: 23 Mar 2013 - Modified: 14 Jul 2012

New features

Many new features have been introduced to this site:
1. More games
The timeframe of this site extended from the last 4 years to the whole era of international club football and beyond. Click on Data on the right to see details.
2. More information
Ev ... (read more)

Created: 23 Mar 2013 - Modified: 8 Jul 2012

Measuring a League's Strength

An often debated question is what the best league in Europe is.
There is no clear answer to that. What is more important, the best teams, the weakest teams? Even an average is not easy to use as the different leagues have different sizes, how can you ... (read more)

Created: 23 Mar 2013 - Modified: 8 Jul 2012

Promotion and Relegation

Clubs that are newly introduced in this system need an initial Elo value to start from.
Being relegated is defined here as not playing for one year because of real relagation or - if the league matches are not available - non-qualification for the Eu ... (read more)

Created: 23 Mar 2013 - Modified: 20 May 2012

Inter-League Adjustments

Teams from different leagues play against each other in European competitions and exchange Elo points. This means that leagues exchange Elo points as well. However, when one observes the leagues' Elo differences over time, it becomes clear that leagu ... (read more)

Created: 23 Mar 2013 - Modified: 22 May 2012

Two-Leg Games

Most of the inter-league competition in European cups is played in two-leg matches. If the standard Elo formula is applied to these games, a serious problem can arise: A team winning its first leg by a high margin can afford to lose the second leg by ... (read more)

Home Field Advantage

In football as in other sports, the home field advantage has a measurable effect that is taken into account in these Elo ratings as well.
If the Elo formulas were applied without any home field advantage adjustment, home teams would win a lot more El ... (read more)

Created: 23 Mar 2013 - Modified: 14 Jul 2012

Weight Index

The weight index determines how many points are exchanged per game. A low weight index (10 or lower) would lead to a long-term-ranking where results from the distant past still have an effect on todays Elo values. A very high value instead would be a ... (read more)

Created: 23 Mar 2013 - Modified: 20 May 2012

Adjustment for Goal Difference

As football is a game of probabilities, where a weaker team can beat a stronger team occasionally, narrow victories are not as significant as landslide victories.
In these Elo ratings, the number of points exchanged will be multiplied with the square ... (read more)

Created: 23 Mar 2013 - Modified: 20 May 2012

Elo Formula

The rankings on this page are calculated with the ... (read more)

Created: 23 Mar 2013 - Modified: 20 May 2012