Scatter graphics: Championship, 10 Dec 2018
With a few managers losing their jobs today and the combination of an FA Cup round and some international fixtures thinning out the domestic fixture list, it felt like a good time to refresh the scatter graphics. These compare the attacking and defensive performances of every team in a division. 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).
With Brentford having imploded somewhat since the early part of the season, Leeds are now the standout side when it comes to shot dominance, taking over five more shots per game than they allow their opponents on average. Their promotion rivals West Brom are certainly fun to watch as a neutral, with over 28 shots raining in during a typical match.
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:
It’s really not been fun to watch Bolton or Ipswich going forward this season: they’ve created the fewest chances and have struggled to convert those that they have carved out. Middlesbrough‘s promotion campaign could yet be undone by some wasteful finishing of their own although, as we’ll see below, their defence has been far more reliable.
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:
With over 19 shots faced for each goal conceded, Middlesbrough‘s defence is in classic Tony Pulis territory: around twice as resilient as the average. Leeds‘ back line is excelling in a different way, with comfortably the fewest shots faced, while poor Ipswich have struggled to keep the ball out of their net despite limiting opponents to respectably few attempts.
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, it’s both Leeds and Sheffield United who are leading the way in performance terms, with actual league leaders Norwich a little way behind. Both Ipswich and Bolton need to add some creativity in January, while Reading, Sheffield Wednesday and Rotherham would be advised to make investments further back.