Scatter graphics: League 2, 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).
There’s no single dominant team in the bottom right of the chart: Newport are shooting the most often but allow a fairly average amount in return while Leyton Orient‘s lack of shots faced isn’t translating into more shots for themselves. Scunthorpe and Stevenage are both spending a lot of time on the back foot.
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:
League leaders Forest Green have been the most clinical finishers , while struggling Carlisle have struggled to turn an above-average number of chances into goals. Northampton are currently sitting in second place despite only five clubs shooting less frequently, thanks to some ruthless finishing of their own.
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:
Tranmere‘s goal continues to live a charmed life, with only three clubs allowing more shots but nobody coming close to their ability to repel their opponents’ efforts. Northampton‘s miserly defence is helping to compensate for their quiet attack.
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 it highlights the enigma that is Rochdale: no team is creating better chances yet somehow they’re sitting in 18th place with a negative goal difference. Swindon and Harrogate have offered plenty of entertainment for the neutral, with quality chances at both ends of the pitch.