Scatter graphics: League 1, 19 Nov 2016

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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Despite their poor start to the season, few teams have been as dominant in shot terms as MK Dons. Only high-flying Sheffield United have registered a more favourable balance of shots taken to shots faced.

Oxford are another side whose dominance hasn’t been reflected in the league table: nobody has created more chances so far this season.

Until recently, Port Vale were sitting in the play-off places despite having taken far fewer shots than anyone else. Their average of just eight per match is over three fewer than the divisional average, which doesn’t bode well.

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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Oldham are having a frustrating season up front, having taken a whopping 21 shots for each goal scored so far: over double the average and over three times what Scunthope – the most clinical finishers – have needed.

Despite creating the most chances, Oxford have needed more attempts to score each goal than anyone except the Latics and Coventry, which goes some way towards explaining why they’re sitting so low in the table at the moment.

Port Vale may not take many shots but they’ve made relatively good use of the opportunities that have come their way, as have the next quietest attackers Southend.

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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Bolton‘s defence looks to be the division’s most effective so far, ranking in the top five for fewest shots allowed and soaking up almost six more attempts for each goal conceded than the average side.

The next two most stubborn defences – those of Oldham and Peterborough – have been kept far busier, with both among the five clubs to have allowed the most shots at their goal.

Millwall have been worryingly leaky despite permitting even fewer shots than the Trotters – perhaps that explains their poor start to the season.

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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Sheffield United have looked the most convincing side so far this season, creating chances of far higher quality than anyone else and second only to Bolton when it comes to limiting the quality of their opponents’.

In the top left corner it’s looking bleak for Shrewsbury, who have allowed over two goals’ worth of opportunities per game: far higher than anyone else and far more than they’ve been creating themselves.