Team Ratings & what good looks like

As Betterbet team ratings are an artificial concept, it’s probably a good idea to go into a little bit more detail about how good a team is to be on a certain team rating.

Below are some screenshots showing “final season” team ratings. These are unadjusted team ratings for an entire league season in the Premier League – so, covering 38 games.

We have data going back to 2000/01 to construct these team ratings from – therefore we have 16 seasons (until the end of the 15/16 season) and with 20 teams playing in each season, we have 320 full season team ratings in the Premier League.

Here are the top 20 full season team ratings during this period in the PL – (you may wish to right click and open in a new tab to view the screenshots better):

The above shows the top 20 PL league seasons since 2000/01 by Team Rating. Chelsea’s 09/10 title winning team under Ancelotti (695) and Chelsea’s 04/05 title winning team under Mourinho (683) are at the top. It’s no great surprise to think that these teams may have been the best two sides in the PL this century – the 09/10 Chelsea side scored 103 league goals and the 04/05 side scored 4.8 goals for each goal conceded.

The middle of the bunch of teams ranked by Team Rating tends to include a lot of average sides, but as you can see, there is a significant difference in where these teams finished in the table. For example, West Ham’s 02/03 side got relegated (with 42 points!) yet had a marginally better rating than the West Ham team that finished 10th in 07/08. Why is this? Team rating is linked to “game dominance” – if teams are having more shots and shots on target than their opponents, then over the long term they should do well. But what if they have strikers who can’t finish, or unusually fragile defences behind them? If the long term is longer than 38 games, then a team may drastically “under-perform” their team rating. The reverse can also apply.

Most teams in the bottom 20 naturally ended up being relegated. The worst Team Rating in PL history since 2000/01 is Derby County’s 363 in 07/08, where they finished with 11 points and ONE win. As they also have the worst rating during the timespan in question, they’re the 0 point on our “Linear Team Rating” stat to the right in the screenshots, which scales each team rating to a number between 0 and 10.

Stoke’s 08/09 side are a notable exception here – they finished with a team rating of 384 which would normally doom them to relegation. However that side played in a defensive, counter-attacking manner in a way that eschewed possession and dominance. They also had the best proportion of any team in the league that season for converting shots on target and saving shots on target they conceded. This is one of the inputs that goes into the Team Ratings. However, as this stat is not normally particularly repeatable, it is not weighted heavily into the overall Team Rating.

The average of all Team Ratings (320) over the last 16 PL seasons is 500.3. There is a reason for this inherent within the construction of the statistic, and the average of a sample (for example 24 teams over the course of a League One season) should always have a mean of 500 (or very, very near). However, the median is often below 500 (in this sample, around 480) due to teams at the very top often being quite a bit better than those in the middle, and those at the very bottom often being a fair bit worse.

This is particularly true in top divisions (as opposed to second or third flight divisions) and in particular in leagues where only two or three teams are truly dominant. Below are the top 20 seasons by Team Rating for Spanish clubs in La Liga – Barcelona and Real Madrid have some very high Team Ratings (700+) but is this because of their greatness or the comparative weakness of the rest of the league?