Scatter graphics: League 1, 7 Feb 2016
Here are updated scatter graphics for League 1, which compare the attacking and defensive performance of each club. These are explained here if you haven’t seen them before.
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).
The top corners of the graphic are home to the division’s main outliers. Starting in the top left, both Crewe and Blackpool have taken among the fewest shots and allowed more than anyone else in return, so both look to be in real danger of dropping into League 2.
In the top right we have the ongoing entertainment of Peterborough, who are massively out-shooting the rest of the division but at the expense of allowing plenty of shots in return.
It looks like someone’s swapped Colchester and Southend around: the former are struggling in the relegation zone despite seemingly dominating matches while the latter remain in the play-off hunt despite regularly allowing more shots than they take.
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:
Strangely most of the teams fall into one of two clusters – a wasteful layer across the top of the chart and a more clinical one beneath. A few prolific shooters like Peterborough, Coventry and Walsall form a breakaway third group to the right.
Two promotion-chasing sides – Gillingham and Millwall have converted their chances at an impressive rate despite taking a relatively average number of shots.
Bradford‘s play-off hopes suffered another blow at the weekend and their attack has let them down this season, with their record in front of goal similar to that of the division’s relegation strugglers.
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:
Burton‘s attack may not be the sharpest but not much gets past their defence. The leaders have allowed few shots and soaked up plenty of those that do get through.
In the bottom left we can see the main reason for Colchester‘s struggles: their defence remains shockingly easy to breach. Withstanding around four shots for each goal conceded is incredibly bad and I genuinely can’t see them staying up at this rate; they haven’t kept a clean sheet since September.
While Blackpool have allowed the most chances per match, they’ve repelled an impressive proportion of them. Both Southend and Peterborough have also got their defences to thank for soaking up lots of punishment.
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:
Blackpool look a lot less doomed when we correct for chance quality, but Crewe remain lodged in the extreme top right of the “bad quadrant”. It will be interesting to see if their recent uptick in form will last.
Despite a recent drop in form, Peterborough remain the most dangerous side going forward but also a danger to themselves at the back.
In the bottom right Burton remain the strongest all-round performances but Wigan aren’t far off, although the Latics look much more formidable in defence than attack.