Scatter graphics: Premier League, 6 Oct 2019
Now that a meaningful number of matches have been played this season, another update to the scatter graphics seems justified. These compare the attacking and defensive performances of every team in a division – each of the four graphics is explained briefly below and at length here.
First of all, here is how the number of shots taken by each club compares with those they face in return. The average number of shots taken per match is on the horizontal and the average number faced is on the vertical, so bottom right (take plenty, allow few in return) is good while top left (take few, allow plenty) is bad. The stripes are like contours: the greener the stripe, the better the performance (and vice versa for red).
Man City are once again the most dominant side, with Chelsea and Liverpool their closest challengers. It’s strange to see both Arsenal and Tottenham allowing so many shots at their goal – only the newly-promoted Aston Villa and Norwich have faced more per match. It’s also interesting to see that Watford rank fourth for shots taken despite their poor start to the season.
Now let’s look at attacking alone. The horizontal axis stays the same as in the graphic above, but now the vertical shows the average number of shots needed to score each league goal. Therefore bottom right is good (taking lots of shots and needing fewer efforts to convert) and top left is bad:
The mystery of Watford‘s position on the previous chart is solved here: while they’ve done a lot of shooting, they’ve also done an eye-watering amount of missing: the Hornets’ attack has been over three times as wasteful as that of the average side. Everton have also struggled to convert an above-average number of chances into goals. Leicester and Bournemouth meanwhile owe their goal tallies more to sharp finishing than dominating matches.
Next let’s look at the defensive situation – basically take the above chart and replace the word “taken” for “faced” on both axes. Now top left is good – facing fewer shots and able to soak up more per goal conceded – and bottom right is bad:
Watford aren’t only the worst finishers in the division so far: they’re also marginally the leakiest at the back, although Chelsea are running them close. There aren’t really any standout defensive records at the moment but both Sheffield United and Crystal Palace are soaking up an impressive amount of shots for each goal conceded.
Finally here’s an attempt at correcting the first graphic for the quality of chances created and allowed, using the same “expected goals” values that power my shot timelines (explained here). The reason for doing this is that the results tend to correlate more strongly with performance than when we treat all shots equally:
When we adjust for shot quality, Man City remain comfortably out in front in attack, although both Liverpool and Man Utd have looked slightly better defensively. Leicester are interesting: despite only three clubs outscoring them so far this season, their total attacking output looks lower than any team except Newcastle.