Scatter graphics: Championship, 2 Oct 2016
With most teams having reached double figures for matches played, it feels like enough time has passed to warrant a refresh of the scatter graphics for each of the EFL divisions. Each of the four graphics is explained briefly below but there’s a longer explanation here.
You can compare how things have changed by looking at the last set I produced 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).
This weekend saw Rotherham cast further adrift into the red top left zone by Newcastle, who lead the way in the opposite green corner. The Millers have allowed around twice as many chances as they have created and unfortunately look overwhelming favourites for the drop.
Two more outliers met yesterday with Nottingham Forest‘s worryingly open defence visiting Bristol City, operators of the division’s busiest attack. While Forest were defeated, it was far from the landslide expected.
Both Sheffield Wednesday and Derby are looking nearly as dominant as Newcastle, although they haven’t been able to sustain the same volume of chances in attack.
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:
Derby have now scored in four successive outings, although not prolifically enough to push them back towards normality on the vertical scale here yet. There are plenty of clubs with similar problems up front, with Fulham‘s wayward finishing undermining what has been the division’s third most industrious attack.
Norwich are the most clinical finishers so far, having needed fewer than seven attempts to score each goal. This is less than half what Aston Villa – themselves also recently relegated – have needed despite taking over a shot more per match, suggesting that the Canaries are adapting better to life at this level.
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:
Brighton‘s defence has proved incredibly difficult to break down so far: yesterday Sheffield Wednesday were the first side to breach it in five games. Birmingham head a cluster of four other clubs – including Ipswich, whose predicament would be far worse otherwise on the evidence of the previous chart – who have also soaked up plenty of efforts for each goal conceded.
While both Sheffield Wednesday and Norwich have allowed opponents few chances, the ones that do get through have been disproportionately likely to find the back of their respective nets. Only a few defences – notably that of struggling Blackburn – have resisted fewer attempts per goal conceded.
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:
Once we correct for shot quality, Newcastle and Brighton look the most dangerous sides overall and could therefore usurp the current top two – more modestly-performing Norwich and relatively serene Huddersfield – in the long term.
Derby are far further to the left here than in the first graphic, which suggests that many of the shots they’ve taken this season have been from poor positions: something that Nigel Pearson’s successor will need to address urgently.
Rotherham‘s predicament doesn’t look any sunnier here than it did in the first graphic – if anything the ratio between attack and defence looks worse and three of their next four games are against teams currently in the top eight.