Scatter graphics: Championship, 6 Feb 2016
Here are updated 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 stick out in the top left and have been overrun this season: the Addicks have faced an average of six shots more per match than they’ve taken themselves.
A more surprising occupant of the “bad quadrant” is Burnley, who are putting together a strong promotion challenge despite being regularly 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. While Hull are contenders for automatic promotion the Royals are languishing in 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:
We look to have two layers of teams here: one of wasteful finishers that sweeps across the top of the graphic and another more clinical bunch beneath. Among these are Blackburn and Bolton who, despite carving out a respectable number of chances, have failed to take advantage and are enduring poor campaigns as a result.
Reading and Nottingham Forest have taken plenty of shots but failed to make them count, but both MK Dons and Bristol City have the additional problem of not creating many opportunities to begin with.
Burnley may carve out relatively few efforts but are leading the way in terms of chance conversion. They, along with Sheff Wed and Fulham, have been far more efficient at finishing than the rest of the division, which explains how the both the Clarets and the Owls are remaining in the promotion hunt despite taking relatively few shots at goal.
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 have been in a class of their own when it comes to soaking up shots. It has taken over twice as many attempts to breach their defence than that of the average club and around three times as many as the division’s most porous back lines – those of Huddersfield and Rotherham.
The next most resilient defences includes those of Hull and Burnley, with the latter – along with Birmingham – sustaining their place in the promotion race thanks to their ability to capably absorb an above-average amount of attempts at their goal.
In the extreme bottom left we find Reading who may be allowing fewer shots at their goal than anyone else but are faring badly at repelling those that their opponents manage to dispatch.
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, therefore undermining their apparent dominance of matches.
This graphic also makes you feel sorry for Bolton‘s creative players. The quality of chances created by the Trotters is on a par with Derby and Brighton but not only are the forwards struggling to finish these off (as we saw in the second graphic above) but the defence is also among the poorer performers, meaning that their efforts have often been for nothing.
In the opposite quadrant, Preston look to be putting safety first: they’ve operated one of the division’s tighter defences but also the third quietest attack, although the net result appears to be working well enough to keep them safely in mid-table.
Charlton still look unhealthily bad overall, with Fulham the next worst all-round performers. We saw in the second graphic that the Cottagers have converted their chances at an impressive rate, but if their strikers were to go off the boil then they’d be in danger of being dragged into the bottom three.
Note: you can also find updated scatter plots every week on the Paddy Power blog, as part of their new “Numerical Advantage” feature: