Scatter graphics: Championship, 10 FEB 2021
Seeing as I last ran them in December it feels like enough time has passed to have another look at 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).
The current top two of Norwich and Brentford have been the most dominant in shot terms, with the Canaries comfortably out-shooting the rest of the division. Bristol City are a bit of a mystery as they sit in the top half of the table despite having the worst balance of shots in the division.
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‘s attack remains the most wasteful in the division, with over 17 shots taken for each goal scored: more than twice that of Reading or Swansea who are flying high despite creating fewer chances. Norwich‘s industrious attack has also been fairly profligate: the Swans are finding the net more frequently despite taking almost six fewer shots per game.
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:
Swansea are also excelling at the back, soaking up more than 19 shots for each goal conceded so far. Fellow promotion challengers Watford and Norwich have also been able to rely on a resilient defence (or goalkeeper at least).
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:
When we correct for shot quality, Brentford and Norwich again set the standard, with the former perhaps the better all-rounders. The Canaries’ supercharged attack is comfortably compensating for a slightly permissive defence. Bottom side Wycombe have a worryingly open defence, while Sheffield Wednesday‘s quiet attack is also a cause for concern.