Scatter graphics: League 1, 14 Jan 2017

It’s been roughly a month since the last set was produced so I’ve updated the scatter graphics, each of which is explained briefly below and at length here.

Shot dominance

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).

2017-01-14-l1-adSheffield United are the division’s most dominant side, although Oxford have created marginally more chances per game so far.

Peterborough remain the most entertaining club for neutrals, with over 27 shots combined raining in per match when they’re involved, compared to around 21 at Bolton.

They may not be in the bottom four but there’s plenty to be concerned about for Port Vale, who take almost four fewer shots per match than the average club and allow plenty in return.

Just like Accrington in League 2, MK Dons‘ presence near the bottom of the table is a mystery given how often they out-shoot their opponents.

Attacking effectiveness

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:2017-01-14-l1-att

Starting at the top, Oldham‘s finishing has been graphic-stretching bad so far: they’ve taken just over 10 shots per game but have needed around twice as many to score each goal.

Contrast that with Scunthorpe, who have required just over six attempts on average to find the net: fewer than half as many as a struggling Coventry side that has created a similar number of opportunities.

The trio of MK Dons, Bradford and Oxford have all failed to make an impressive number of shots count – all could perhaps be sitting higher in the table if they’d been able to find the net a bit more reliably.

Defensive effectiveness

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 Bradford may be struggling to convert their chances, only Bolton have been making life more difficult for opposing attackers this season. The next most stubborn defence has been that of Oldham which, combined with their own problems in front of goal, has meant little entertainment for the goal-seeking neutral.

In the bottom left, both Millwall and Bristol Rovers have been better than average at restricting their opponents’ chances but have been equally bad at repelling the shots that do get through.

Expected goals

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:


While Oxford create marginally more chances than leaders Sheffield United, once we correct for shot quality they look a lot more ordinary and it’s the Blades who stand head and shoulders above the rest.

Interestingly Scunthorpe don’t look to be dominating matches all that much: as we saw in the previous two graphs, their promotion challenge is being powered by some clinical finishing and stubborn defending. Historically this hasn’t proven to be all that sustainable, so they may need to find another gear in order to remain in the top two.

Port Vale‘s attack looks less unusually bad than it did in the first graph (when we just measured shot quantity), but along with Walsall and Shrewsbury in particular they still look to be in a precarious state overall.