Scatter graphics: League 1, 14 Dec 2021
It’s been inexcusably long since I refreshed the scatter graphics, so here’s a full pre-Christmas set. 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).
Rotherham are the division’s most dominant team at the moment, with nobody else anywhere near them. Ipswich games have been low on action with just over 20 shots on average, compared to almost 29 in matches involving Wycombe.
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:
Doncaster‘s attack is worryingly behind the rest of the division at the moment: creating the fewest chances and the worst at converting shots into goals. While Ipswich have taken the third fewest shots per match, they’ve been the most effective when it comes to beating the goalkeeper.
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:
There aren’t any crazy defensive outliers in the division at the moment. Ipswich would be sitting higher in the table if they didn’t concede so readily from the few relatively few shots they’ve conceded, while Wycombe are maintaining a promotion challenge due to how well they’ve dealt with a relatively high number of chances allowed.
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:
Adjusting for shot quality, Rotherham are still streets ahead of the rest, so if they don’t secure promotion this season it will be a huge disappointment. It’s easy to see why Crewe and Doncaster are the current bottom two: the former need urgent defensive improvements while the latter need to add a spark in attack.