Scatter graphics: Championship, 2015/16 season
Now that the “regular season” is over in the Championship, here are the final set of scatter graphics. These compare the attacking and defensive performance of each club: they are explained here if you haven’t seen them before and the previous instalment is 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).
Tackling the outliers first, Charlton have made the undesirable top left corner their own this season. It’s been a horrible campaign for the Addicks, who have taken fewer shots than anyone except fellow relegatees MK Dons and allowed far more than any other club.
In the opposite corner we can see that Hull were the division’s most dominant side: they took more shots and allowed fewer than anyone else, so it’s a surprise that they weren’t able to secure a top two finish. Next to them are Reading, who despite finishing 17th were second on both metrics; we’ll see how that works a bit further down.
What’s even more surprising is that Burnley won the title despite ranking fourth “worst” for both shots taken and shots faced. However this gets a lot less surprising when we look at the rest of the graphics.
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:
Straight away we can see why Burnley didn’t need to take many shots to win the title: their finishing was utterly ruthless. In the top right we can see another example of quality beating quantity: Reading may have taken lots of shots but they were incredibly wasteful when it came to converting them. However Nottingham Forest found it even harder to find the back of the net this season.
In the top left we find all three relegated clubs – MK Dons, Bolton and Charlton – who all struggled to both create and convert chances. Fulham‘s much sharper attack looks to have kept them out of danger.
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:
While Nottingham Forest may struggle to score goals, both they and Birmingham are pretty adept at stopping their opponents from doing likewise despite having plenty of shots to repel. In the opposite quadrant we can see that Reading – along with Huddersfield – may have allowed few shots but struggled to deal with those that got through.
While Fulham‘s attack was among the more clinical on the previous chart, we can see here that they made their opponents look like pretty sharp finishers too.
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, Hull‘s inability to hold onto a top two place looks all the more frustrating, with both Derby and Brighton also able to air legitimate grievances about having to run the play-off gauntlet.
Burnley look far more respectable here, which suggests that they took shots of above-average quality and tended not to allow their opponents many shots from good positions. However they’re still a long way away from the aforementioned clubs in the bottom right corner, so it will be interesting to see if they can repeat the trick in the Premier League next season.
I feel a bit sorry for Bolton, who looked pretty respectable going forward only to be let down by some inaccurate finishing and a leaky defence. Blackburn and Huddersfield also look to have underachieved based on their underlying performances, so it wouldn’t surprise me to see both finish higher next time around.
On the flip side, it’s interesting to see Birmingham – who secured a top half finish – ranking 20th in both attack and defence. I’m not sure what Gary Rowett is doing but he’s kept that side overachieving ever since he arrived.
Note: it’s my aim to expand on this with a club-by-club review of the season for all three Football League divisions (and the National League if I get time) in the coming weeks.