Scatter graphics: League 2, 20 Oct 2016
Below is the latest refresh of the scatter graphics, each of which 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).
Blackpool and Portsmouth have been the division’s two most industrious attacks, with Pompey also leading the way defensively with the fewest shots allowed.
While Mansfield are matching their stinginess at the back, they’ve not been able to pair this with much forward raiding.
Despite taking slightly more shots than the Stags, Morecambe have allowed over twice as many shots: an eye-watering average of 18 per 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:
While Blackpool and Portsmouth are the busiest sides going forward, neither has acquired the knack of converting their chances efficiently. The Tangerines in particular are among the most wasteful finishers, on a par with bottom side Newport and only slightly better than Leyton Orient.
The current top two of Plymouth and Doncaster look to have profited more from sharp shooting than outright domination, with both among the division’s three most clinical sides. Hartlepool are edging both of them however, although only Crawley have created fewer chances 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:
Plymouth’s defence remains the division’s most resilient, although fellow promotion challengers Carlisle and Luton have also proved difficult to break down this season.
While Portsmouth allow opponents fewer chances than anyone else overall, nobody has conceded more readily from the shots they’ve faced – a problem shared to a lesser extent by Doncaster and Accrington this season.
Morecambe’s extreme permissiveness at the back has been slightly tempered by some resilient defending, but nowhere near enough to compensate for the sheer volume of efforts faced.
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:
Portsmouth remain the most impressive all-round performers, although without improved execution at both ends of the pitch this may not be enough to close the gap at the top of the table.
Luton and Doncaster are the next most convincing overall, but look stronger in attack than defence, while fellow challengers Plymouth and Accrington are the opposite.
In the bottom left, Mansfield’s safety-first approach has seen them achieve a relatively healthy balance, even if the results aren’t always entertaining.
Newport look to be in real danger of dropping into the National League, while Wycombe also remain in danger despite a recent upturn in form. The insulation provided by Morecambe’s strong start is also being gradually stripped away: the chances they’ve allowed translate into a worrying two goals conceded per game over the long term, close to the 23 they’ve shipped in 12 matches so far.