Scatter graphics: League 1, 8 Oct 2017
Here’s another update to 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).
Wigan continue to be the most dominant team in the division by far, with only Peterborough taking more shots per match and nobody allowing fewer in return (although Doncaster come the closest).
At the other end of the spectrum it’s looking concerning for both Gillingham and Northampton, who are both allowing far more chances than they’re creating themselves.
Wimbledon games have been low on action so far, with an average of around 20 shots taken at both ends combined, compared to over 29 at Peterborough.
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 have had a horrible time in front of goal this season, and it’s not exactly been a picnic for Gillingham either, with both having needed over twice as many attempts to score each goal as the average team so far.
Meanwhile Fleetwood have created even fewer opportunities – only Northampton have troubled opposing defences less frequently – but have been impressively ruthless at finding the net. The Cod Army have scored more goals than Charlton despite taking almost six fewer shots per match on average.
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:
Scunthorpe‘s finishing may be far more wasteful than last season but their defence has been incredibly hard to break down. Shrewsbury and Blackburn have also dealt capably with a relatively average number of opposition chances.
Meanwhile Southend have struggled to keep the ball out of their net, with only Oldham‘s defence soaking up fewer shots per goal conceded on average shots than the Shrimpers.
Doncaster have looked impressively well-organised on their return to this level, allowing fewer shots than anyone except Wigan, but have found it difficult to deal with the chances that their opponents do manage to carve out.
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 correct for chance quality Wigan look even more impressive, with the best attack and defence. Four attacks – those of Peterborough, Southend, Bristol Rovers and Rotherham – are performing nearly as well, although all except the Millers look below-average defensively.
Doncaster s performances suggest that they’re capable of sitting far higher in the table than their current 17th position, with an above-average attack and one of the best defences in the division.
At the time of writing, the relegation zone currently contains the four worst-performing teams overall which – while reassuring for my model -doesn’t offer much hope for those teams. Interestingly bottom side Plymouth look to be in marginally less trouble than the other three.