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Elo Ratings

Elo Ratings 2013-2014 Season

End of season Elo Ratings are now updated for English and Scottish leagues. In the English premier league Liverpool gained 122 points on their Elo rating compared with the start of the season.

Southampton, Crystal Palace and Stoke also increased their Elo rating this year. The premier league’s biggest underachievers were of course Man United with an Elo rating down -117 points on the start of 2013/14.

2013/14 Team Elo Ratings – English Premier League

Elo ratings showing current rating and also the number of Elo points gained or lost in each team’s final league game in the 2013-2014 season

English Premier League 2013 – 2014
Date Team Rating Last Game
11 May 2014 Man City 1778 2
11 May 2014 Chelsea 1721 3
11 May 2014 Liverpool 1718 2
11 May 2014 Arsenal 1673 7
11 May 2014 Man United 1652 -2
11 May 2014 Everton 1629 8
11 May 2014 Tottenham 1596 5
11 May 2014 Southampton 1502 2
11 May 2014 Stoke 1476 11
11 May 2014 Swansea 1450 18
11 May 2014 West Ham 1426 -2
11 May 2014 Crystal Palace 1422 0
11 May 2014 Sunderland 1413 -18
11 May 2014 Newcastle 1409 -2
11 May 2014 West Brom 1399 -11
11 May 2014 Aston Villa 1380 -5
11 May 2014 Norwich 1366 -7
11 May 2014 Hull 1361 -8
11 May 2014 Fulham 1342 0
11 May 2014 Cardiff 1287 -3

For the start of the 2014/2015 season and once all the playoffs are settled I’ll look at the adjustments needed for those teams involved in the promotion and relegation places.

Elo Points Gained or Lost in English Premier League

Total number of Elo Rating points gained or lost since the beginning of the 2013-2014 season

English Premier League 2013 – 2014
Date Team Elo Points
11 May 2014 Liverpool 122
11 May 2014 Southampton 85
11 May 2014 Crystal Palace 74
11 May 2014 Man City 73
11 May 2014 Chelsea 54
11 May 2014 Stoke 53
11 May 2014 Everton 31
11 May 2014 Hull 13
11 May 2014 Swansea 12
11 May 2014 West Ham 3
11 May 2014 Arsenal 3
11 May 2014 Sunderland -4
11 May 2014 Newcastle -18
11 May 2014 Tottenham -49
11 May 2014 West Brom -51
11 May 2014 Aston Villa -54
11 May 2014 Cardiff -61
11 May 2014 Norwich -70
11 May 2014 Fulham -99
11 May 2014 Man United -117

Elo Team Ratings

Categories
Elo Ratings

Elo Match Rating System

Match Ratings

Currently I am producing match ratings for English (including Conference) and Scottish leagues.

The method I use is based mainly on articles found on clubelo.com. I say mainly as there are some differences. My ratings only take league games into account. FA cup, League cup, European matches and friendlies are not included.

I also apply a static home advantage of 90 points for English games and 50 points for Scottish games. Match ratings for English and Scottish league games start with the 2000/2001 season.

Team ratings

Elo Ratings

Calculating the Team’s Elo Rating

Match ratings are generated using Team Elo ratings therefore team Elo ratings where calculated a couple of seasons earlier than the match ratings starting with the 1998/1999 season. Each team in the four English and Four Scottish divisions are given 1,500 Elo points for the start of the 1998/1999 season.

As the fixtures progress the changes in the team rating begins to reflect the strength of each team relative to the other teams in the division.

Elo Team Ratings

Ratings for the Conference league started with the 2005/2006 season.

Relegation and Promotion

At the end of each season an adjustment is made to deal with teams that are relegated and promoted. In order to keep the number of points in each division constant I have opted to simply reallocate the total points of the division’s relegated teams and assign them between the newly promoted teams and vice a versa.

This may not be the best approach particularly when a division has only one promotion spot like the Scottish Premier. At some point I’ll look closer at how relegated and promoted teams perform in their following season.

Rating Factors

A team’s new Elo rating is recalculated after each league game with the new rating depending on a number of factors. These include:

  • The team’s old rating
  • The Elo points difference between the home and away team
  • The result of the match
  • The expected result of the match
  • The goal difference of the match
  • An adjustment for home advantage

A team’s rating may increase or decrease or occasionally stay the same.  Rating points are exchanged between the two sides. For example, if a home team’s rating is increased by 7 points then the away team’s rating is decreased by 7 points.

A match rating for the next game is created by simply taking the home team’s Elo rating and subtracting the away teams’s Elo rating. A high positive number indicates that the home team is the stronger team and a high negative number indicates that the away team is stronger.

My next task is to understand Bivariate Poisson Distribution to calculate probabilities and odds for match results and correct scores.