The Premier League is highly competitive and an analysis of the first half of the season shows that it moving up the league requires significant performance improvement.
This weekend marked the halfway stage of the Premier League for most clubs (although Covid postponements have not made it a perfect split). Since most teams have now played 19 games, it seems like a perfect time for a half-term report.
By comparing the league table with the same time last year we can see who has improved, who is getting worse, and who is just the same.
Of the seventeen clubs who played in the league last year, seven have improved their position, nine have slipped down the league, and one (Arsenal) has stayed in the same place. This is shown in the chart below that plots changes in position along the horizontal axis and changes in points per game along the vertical axis.
The chart also shows the significant relationship between increasing points per game and position. Basically, it is a competitive league and if you want to seriously move up the league you have to dramatically improve your performance. This is not a league where you get ahead by standing still.

Winners and Losers
The biggest winners have been Aston Villa and West Ham, who have both increased 10 places with an extra average points per game of 0.8 and 0.6 respectively.
The other group of happy supporters are to be found in Manchester and Liverpool. Although there is now a reversal of fortunes from recent years, with Man Utd sitting on top of the league (6 places better with an extra 0.6 points per game) while Everton have improved seven places with an even better 0.7 extra points per game.
As for their neighbours, Man City are pretty much the same as last year (and therefore still dangerous in second), while Liverpool have dropped three places.
For the last couple of years Liverpool have been so good that they seemed to be the outliers in every statistic. The same is true here, but this time they are outliers in going backwards. They have the second biggest drop in points per game (1.1 points per game less than last year) but have only dropped three places, whereas Sheffield United who have dropped 1.3 points per game are now 13 places worst off. The difference of course is that Liverpool where so far ahead last season its like they have now reverted to the mean.
As for the other not enjoying their season, the teams who have lost the most ground this year include Wolves (nine places), Chelsea and Newcastle (both five places), and Crystal Palace and Burnley (both four places).
Of course this is only half-time, so it will be interesting to see where they all end up at the end of the season.