Scatter graphics: Championship, 20 Nov 2016
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).
Let’s start with the elephant in the room: Rotherham are in a horribly unhealthy place in the top left of the chart and are in serious danger of being relegated at this rate, facing on average nine more shots per match than they’re taking.
In the opposite corner, things are looking pretty rosy for Newcastle, who allow the fewest shots of any second tier side and take more than anyone except Bristol City.
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:
Newcastle are the standout attacking performers: while Bristol City create marginally more opportunities, they need around four more attempts to find the net than the title-chasing Magpies.
While they’ve undoubtedly improved since Steve McClaren’s return, Derby remain the division’s most wasteful finishers on average, although that’s not likely to be the case the next time we revisit these graphics. Their current position has been skewed by their hilariously bad start.
While Sheffield Wednesday and – more impressively – Burton have created plenty of chances this season, they’ve also been let down by some wasteful finishing so far.
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:
Rotherham‘s poor performance is stretching the graph in one direction and Brighton‘s impressively resilient defence is pulling it in another, cramming the other 22 teams into a relatively small space. The Seagulls have soaked up over 19 shots for each goal conceded, which is almost eight more than the average side.
At the bottom of the graphic we can see how a leaky defence has cost Norwich this season: only five clubs have allowed fewer chances than the Canaries but fewer than one in seven shots ends up in the back of their net.
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:
Things don’t look much better for Rotherham when we adjust for shot quality, with around a goal’s more worth of chances faced than created. Despite a respectable defence, Ipswich are also struggling to carve out good opportunities this season.
Newcastle are unsurprisingly leading the way here: while both Derby and Brighton are matching them defensively and Bristol City aren’t too far behind them in attack, only the Magpies are managing to excel on both fronts at once.
While Huddersfield have also maintained one of the Championship’s tougher defences, this has come at the expense of their attack and a different balance may need to be struck if they are to stay in the promotion race. The opposite applies to Reading and Burton, who are faring well up front but look vulnerable at the back.