Scatter graphics: Championship, 21 Mar 2016
Ahead of the Easter weekend I thought it was a good time to update the scatter graphics for the Championship, 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).
Poor Charlton continue toi stick out in the top left and have been overrun this season: the Addicks have faced an average of around six shots more per match than they’ve taken themselves.
A more surprising occupant of the “bad quadrant” is Burnley, who are now promotion favourites despite regularly being out-shot. The next two graphics will show how they’ve managed this.
Moving over to the “good quadrant” in the bottom right, Hull and Reading have been the division’s most dominant sides in shot terms. While Hull remain contenders for automatic promotion, the Royals are languishing in lower mid-table, with the fourth graphic in this post illustrating best how they can be performing so differently.
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:
In the top right, Reading and Nottingham Forest have taken plenty of shots but failed to make them count, with Forest by far the most wasteful. They’ve taken around five more shots for each goal scored than the average club.
Burnley may carve out relatively few efforts but are leading the way in terms of chance conversion. They’ve been over twice as efficient as Forest and – along with Sheff Wed and Fulham – far more ruthless in front of goal than the rest of the division.
It’s frustrating for Huddersfield that they’ve been as effective as second-placed Brighton up front but are 26 points worse off: the next graphic will show why.
MK Dons and Charlton look significantly off the pace here, having taken far fewer shots than anyone else and not converting them particularly effectively.
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:
Middlesbrough and Hull have been by far the best defensive performers, allowing few shots and soaking up a heroic amount for each goal conceded. Leaders Burnley have been similarly resilient but have allowed far more attempts at their goal.
It has taken over twice as many attempts to breach the defences of these three than the division’s most porous back lines. Among these is Huddersfield, whose attacking exploits and impressive ability to restrict their opponents’ opportunities has been undermined by conceding more readily than anyone except Bolton.
Charlton again look exceptionally poor here, faring badly at repelling the many shots they’ve faced.
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:
One of the major differences from the first graphic is the position of Reading. They were alongside Hull in the bottom right corner before, when all we were interested in was the quantity of shots, but when we correct for quality they lurch sharply back towards the middle. This suggests that the average quality of the shots they’re taking is low and the ones they’re facing high, meaning that their apparent dominance of matches doesn’t count for much.
In the opposite (top left) corner, Charlton look just as doomed as they did before, although both Fulham and Rotherham look to have allowed a similarly worrying volume of chances.
Both Cardiff and Bolton have performed relatively well when it comes to creating chances, but their defences have looked vulnerable. It’s interesting that the Welsh side have handled this situation so much more effectively.
Sitting alongside the likes of Burnley and Middlesbrough in the bottom right, Blackburn and Huddersfield look as though they should at least be in the top half of the table.