Scatter graphics: League 1, 4 Mar 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).

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Leaders Sheffield United have been the division’s most dominant team – while Oxford and Bradford can match them for chance creation, nobody comes close on the defensive side.

Peterborough matches remain the most entertaining for the neutral, with an average of around 26 shots taken per match compared to around 21 when Fleetwood and Bolton are involved.

Port Vale continue to create worryingly few chances: over a shot per match fewer than anyone else in the division.

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:

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While Oxford and Bradford can match Sheffield United for the number of shots taken, they’ve been quite some way behind the Blades when it comes to converting those chances.

Only three clubs have been more wasteful in front of goal – the worst performers are Oldham who also take fewer shots than everyone except Port Vale.

Scunthorpe were scoring for fun earlier this season but this had more to do with clinical finishing than attacking dominance. Even though they’ve gone off the boil a bit lately, the Iron remain the most efficient finishers overall.

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:

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The promotion-challenging trio of Bolton, Fleetwood and Bradford have all performed well at the back this season, allowing fewer shots than average and soaking up plenty for each goal conceded.

While Oldham have struggled to convert their chances, they’ve also absorbed more shots for each goal conceded than anyone else and have the best defensive record besides the aforementioned three clubs at the opposite end of the division.

Both Rochdale and Bristol Rovers have seen their promotion challenges undermined by some leaky defending: no clubs have absorbed fewer shots for each goal conceded.

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:

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When we correct for shot quality, Sheffield United look even more dominant, with Bradford and Oxford no longer matching them in attack. This suggests than the Blades have been far better at shooting from good positions than the other two.

The latest occupants of sceond place – Fleetwood – are interesting as while they have a good defence they don’t create a lot of chances, although they’re not far away from either Bolton or Scunthorpe, who also seem better at defending than attacking.

However it looks like both Bradford and Millwall have it in them to finish strongly, so the promotion race could have a dramatic conclusion.