Scatter graphics: League 1, 2018/19
Now that the regular season is over, here’s a final batch of the scatter graphics, which 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).
Barnsley were comfortably the most dominant side in raw shot terms, although champions Luton also stood out from the crowd. Interestingly five of the remaining six sides in the ‘dominant’ bottom right quadrant finished outside the play-off places. Peterborough have been an enigma this season, creating a relatively average number of chances and allowing a seemingly unhealthy amount in return, so it’s not surprising that their promotion bid faltered.
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:
Wimbledon left it late to secure their survival and their attack was their main problem this season, having created the fewest chances and being among the most wasteful finishers. Bristol Rovers had a pretty frustrating time in front of goal themselves, having created more chances than Charlton and Sunderland but needing around four to five more attempts on average to find the net.
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:
Not only were Charlton among the division’s most ruthless finishers but they also proved the most difficult side to break down at the other end, having soaked up around four more shots for each goal conceded compared to the average team. While the likes of Burton, Oxford and Shrewsbury allowed their opponents relatively few chances this season, it usually didn’t require that many attempts to breach their defences.
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 looks like the correct teams finished in the automatic promotion places: Luton and Barnsley are almost inseparable in the bottom right corner. Burton can be disappointed not to have made the play-offs and Shrewsbury can legitimately hope for better than 18th next season. Fleetwood look to have been impressively solid at the back but perhaps at the expense of their attacking output.