Scatter graphics: League 2, 2016/17

Now that the regular season is over here’s a final version of 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).

Portsmouth‘s title win wasn’t all that surprising given how much they’ve dominated matches this season. Doncaster – along with Mansfield – matched them in defence but created far less themselves.

The relegated due of Leyton Orient and Hartlepool spent a lot of time on the back foot this season, although not as much as Morecambe. I’d also be a bit concerned if I were a Crawley fan.

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:

Doncaster and Exeter may not have created that many chances but they were extremely clinical in front of goal. The opposite was true of both Accrington and Barnet, who took plenty of shots but were the most wasteful finishers in the division.

While Crawley and Hartlepool carved out fewer attempts than anyone else, both were at least efficient with the ones they did fashion.

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:

The trio of Luton, Plymouth and Blackpool – all of whom finished in the top seven – did an excellent job of repelling their opponents’ shots this season.

Doncaster allowed opponents fewer chances than anyone except Portsmouth but struggled to deal with those that did find a way 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:

Compared to the first graphic Doncaster have shot all the way over to the right, suggesting that they’ve focused on quality over quantity with their attacking this season.

It’s interesting that Plymouth – who could have won the title on the final day – look pretty average here. It’ll be interesting to see how they get on in League 1 next season.

Carlisle have a strong attack but also a weak defence, which explains their struggle to stay in the promotion race. Meanwhile Mansfield had the opposite problem – a strong defence but a middling attack – and narrowly missed out on the top seven.