Scatter graphics: League 2, 17 Jan 2016
Here are updated scatter graphics for League 2, which compare the attacking and defensive performance of each club. These are explained here if you haven’t seen them before.
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).
Two of the current top seven, Northampton and Wycombe, have sustained a promotion challenge despite taking fewer shots than the average team and far fewer than the clubs around them at the top of the division.
It’s been incredibly difficult to get shots away against Portsmouth, who have allowed around five fewer per match than the average side.
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:
Northampton may not take that many shots but they’ve made excellent use of the ones they have carved out. Along with Morecambe they’ve been far more clinical than the rest of the division, needing just over five shots to score each goal.
The current bottom five are also the occupants of the “bad quadrant” here (although Newport are a borderline case), having taken few shots and needed lots of chances to find the net.
Hartlepool have been the division’s most wasteful finishers, marginally more so than Bristol Rovers who have fired in four more efforts per match.
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:
Among the cluster of other strong defensive performers we find Wycombe and Northampton – along with Mansfield – who have all kept pace at the top end of the division thanks to their solidity at the back.
Despite being lodged among the busiest shooters in the last graphic, Notts County have been among the worst performers at the back, with a record similar to the current bottom three.
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:
Stevenage are almost smashing into the title at the top: their defence has been the division’s most permissive by some distance this season. At the bottom, both Wimbledon and Portsmouth have allowed roughly half the quality of chances in an average match this season.
The current bottom three of York, Yeovil and Dag & Red have been the three worst performers overall, so unfortunately at the moment it looks like two of them will be filling the relegation spots at the end of the season.
Both Notts County and Carlisle look to have seen strong attacking showings undermined by leaving themselves open at the back.