Scatter graphics: Championship, 17 Sep 2017
As every EFL club now has now played a decent number of matches, it’s borderline-justifiable to chuck their data into the scatter graphics to see how things are shaping up. 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).
Brentford may be in the relegation zone but they’ve been the most dominant team in the division so far, carving out over 18 shots per match and facing fewer than 11 in return, so I suspect that they’ll start climbing the table soon.
Burton and Ipswich meanwhile have been on the back foot to a far greater extent than anyone else: both have created fewer than 10 chances per match and allowed almost 20. The Tractor Boys are currently sitting in fifth, which suggests that they’re auditioning to be this season’s Reading.
Bristol City are the division’s entertainers at the moment, with their matches seeing an average of over 30 shots compared to the shade over 20 you get when Middlesbrough or Bolton are involved.
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:
I can’t pretend to care much for Harry Redknapp, but whoever takes over from him at Birmingham will benefit when their unsustainably bad shot conversion rate starts to approach normality.
We can also see one reason why Brentford aren’t higher in the table, and while I think that Bolton‘s finishing should also improve as the season goes on, their transfer embargo makes their poor performance easier to explain.
Ipswich‘s ruthless finishing – they’ve been around four times as clinical as Birmingham so far – has contributed to their strong start, but again I don’t expect such an extreme ratio of shots to goals to persist over the rest of their campaign.
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:
Leeds and Preston are soaking up an impressive – and again probably unsustainable – amount of shots for each goal conceded, but with both sides allowing few chances their defences could well continue to outperform the division.
Again we have Ipswich looking either fortunate or doing something special: despite allowing more shots than anyone else they’re absorbing lots of punishment. Sheffield United‘s defence has also been repelling quite a few chances for each goal conceded: a rate that is unlikely to continue.
Bolton, Hull and Brentford meanwhile have all been allowing relatively few chances but conceding frequently, so it’s probable that all three have suffered a bit of bad luck so far.
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:
Leeds‘ and Cardiff‘s strong starts are no fluke: both have been among the division’s best performers overall. Alex Neil also looks to be doing a great job of restoring his reputation at Preston and Millwall deserve a mention for their impressive return to the second tier.
Burton look to be in the most trouble so far: they’re not creating much at all and are giving their opponents over two goals’ worth of chances per game, so unless they can get on the front foot a bit more I worry that they’ll get dragged into the bottom three.
Sheffield United are sitting in the top six at the time of writing but look to be adopting a “safety first” approach that may see them struggle to score enough goals to stay there.