The Eastwood Index, MLS and Parity

Posted by Martin Eastwood May 7, 2013 3 Comments 2520 views

I showed in my last post how Major League Soccer (MLS) is a much more closely matched league than the English Premier League (EPL), with the wage cap and draft system increasing the parity between teams.

The Eastwood Index

This high level of parity can also be seen using the Eastwood Index (EI), a rating system designed to calculate odds of match outcomes when different teams play each other.

The Eastwood Index rates teams so that the average rating is 2000 and the higher the rating the better a team is compared with the rest of the league.

EI ratings increase when teams win matches or draw against superior opposition and decrease when teams lose matches or draw against weaker opposition. The size of the gain or loss in ratings is linked to the quality of the opposition so that beating a superior team is worth more than winning against a lower ranked team.

The change in EI rating is also weighted by the goal difference in the match so that the greater the difference in goals scored or conceded then the greater the change in ratings. Home advantage is also included in the calculations so that the home team is expected to perform better when playing at home compared with away.

Major League Soccer EI Ratings

Currently, the highest rated team in MLS is LA Galaxy, with an EI of 2506 (Table 1) while the lowest is Toronto FC, with an EI of just 1303 (Table 2). Outside of this, the majority of teams are fairly evenly matched in MLS and are rated around 1880 – 2300 demonstrating the parity in the league.

Table 1: MLS Eastern Conference EI Ratings
Position Club EI Rating
1 New York Red Bulls 2225
2 Sporting Kansas City 2374
3 Houston Dynamo 2210
4 Montreal Impact 2052
5 Columbus Crew 2082
6 Philadelphia Union 1809
7 New England Revolution 1610
8 Chicago Fire 2063
9 Toronto FC 1303
Table 2: MLS Western Conference EI Ratings
Position Club EI Rating
1 FC Dallas 2150
2 LA Galaxy 2506
3 Real Salt Lake 2271
4 Portland Timbers 1804
5 Colorado Rapids 1871
6 Chivas USA 1433
7 San Jose Earthquakes 2267
8 Vancouver Whitecaps 1690
9 Seattle Sounders FC 2392

It is still a bit early in the season to draw too many conclusions but if we combine the two MLS conferences together then Columbus currently come out as mid-table, with an EI rating of 2082. This is just 424 lower than the top team (LA Galaxy) and 569 higher than the bottom of the league (Toronto FC), and close to theoretical league average EI of 2000.

MLS Compared with EPL

Compare this with the EPL (Table 3) and you can see an immediate difference in the level of parity. Taking the average of West Ham and Stoke to be the middle of the table then a mid placed EPL team’s EI is below the theoretical average at 1634, just 264 better than QPR at the bottom of the table and a gigantic 1431 away from  Manchester United. The top of the EPL has been very much a league-within-a-league for a while now, with average teams vastly more likely to be relegated than they are of ever winning anything or even reaching the European qualification spots.

Table 3: EPL EI Ratings
Position Club EI Rating
1 Manchester United 3064
2 Manchester City 2909
3 Chelsea 2598
4 Arsenal 2627
5 Tottenham Hotspur 2514
6 Everton 2351
7 Liverpool 2291
8 West Bromwich Albion 1883
9 Swansea City 1797
10 West Ham United 1520
11 Stoke City 1747
12 Fulham 1806
13 Aston Villa 1704
14 Southampton 1611
15 Sunderland 1741
16 Norwich City 1607
17 Newcastle United 1814
18 Wigan Athletic 1650
19 Reading 1397
20 Queens Park Rangers 1369

Parity

Compared with the EPL, MLS is a very evenly matched league where the margins between the top and bottom of the conferences are small, making it a really exciting league to follow as virtually any team is in with a chance of reaching the playoffs at the start of the season.

 

About Martin Eastwood

Martin is football fan and data scientist. In his spare time he likes to combine the two and write about the mathematical analysis of football.

View all post by Martin Eastwood

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  1. Pingback MLS EI Supporters’ Shield and Playoff Qualification Forecast (May 13, 2013) | NewsCred Plugin For WPMU

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Write Your Comment

  • Martin Eastwood

    Thanks, I'll be taking a look at that soon! …

  • Antony Lee

    think the model fitted is much better now, as the …

  • Martin Eastwood

    Thanks, it's something I'd like to include but I'v …

  • Brendan

    This is very cool Is it possible to make the ob …

  • Pete

    Interesting - I always wondered what would the per …

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