Are Chelsea Improving Under Graham Potter? We Take A Look At The Numbers

Content Editor

1 year ago

With Chelsea languishing in midtable, there has been an ongoing argument among supporters about whether manager Graham Potter is the right man to bring success to the Blues.

Some have argued that Potter’s methods take time to come to fruition but we wanted to look at the stats to see if there has been any discernable progress since he was appointed back in September.

To do this, we decided to compare a number of statistics before and after the World Cup which could give us an indication as to whether Potter is getting his ideas across to the players.

Press the next page as we look at whether Chelsea’s underlying numbers are improving under Potter.

Goals For And Against

The Blues were averaging 1.125 goals a game in the eight league matches before the break for the World Cup. In terms of conceding, they averaged exactly one per game.

After the tournament in Qatar, Potter’s side have scored 0.71 goals per game, and conceded 0.57 per 90 minutes.

It means that, while Chelsea have tightened things up at the back, they have actually gone backwards in the final third of the pitch.

Expected Goals (xG) and Expected Goals Against (xGA)

These metrics may give us a fairer assessment of how things are progressing under Potter as they are not reliant on luck, finishing ability or other factors.

Before Christmas, the Blues’ total xG from eight matches was 7.9 (which is an average of 0.99 per game), after Christmas, the total xG from seven games was 9.6 (which is an average of 1.37 per match). There is a noticeable improvement in creating chances following the World Cup.

In terms of xGA, the total conceded prior to the tournament in Qatar was 10.9 (which averages 1.36 goals conceded per 90), after the World Cup, the total xGA conceded was 7.7 (with an average of 1.1 goals conceded per 90). Again, there is a slight improvement at the back.

Possession

Potter is known for developing possession-based teams, so an increased possession percentage should indicate that Chelsea are becoming a more ball-dominant side.

Prior to the break in domestic football, the Blues had 56% of the ball in the eight Premier League fixtures with Potter at the helm. In the seven matches after the break, that number has increased to 58%.

Of course, it is a small sample size, and it also depends on the teams you are facing, but it shows some progress is being made.

Expected Points (xPTS)

While they say the table doesn’t lie, bad luck and refereeing decisions, combined with other factors can have an influence on results. The expected points metric is, therefore, a good way of looking at how a team is actually performing.

In eight league matches prior to the World Cup under Potter, Chelsea accrued 11 points, but in terms of xPTS (8.20), they actually overperformed; demonstrating how poorly they were playing.

Since Christmas, their xPTS suggests they should have picked up an average of 11.57 points from seven matches, rather than the paltry 9 they’ve secured. From a purely statistical point of view, therefore, Potter’s team IS performing better than it did before the World Cup.