Season update: National League, 22 Dec 2015

Ahead of the busy festive schedule, I thought that it was a good time to take another look at how each of the National League clubs are performing using my scatter graphics. These are explained here if you haven’t seen them before.

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:

NL att def 2015-12-21

While Wrexham and Grimsby may be off the pace in the promotion race, both have consistently dominated matches this season.

The only team to have taken more shots than these two are Woking, although they’ve also allowed opponents a relatively high number in return: around one more per game than the average.

It looks as though Altrincham have spent plenty of time on the back foot this season: they could be in danger of being dragged into the relegation battle.

Matches involving Eastleigh, Braintree and Gateshead all seem to be on the quiet side this season, with fewer shots than the average at both ends.

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:

NL att eff 2015-12-21

 

Despite taking a very similar number of shots overall, Eastleigh and Altrincham have enjoyed differing fortunes in front of goal. The former are the division’s most clinical side while the latter are the most wasteful, needing almost twice as many attempts to score each of their goals.

A similarly profligate side, Barrow, partially compensate for their inconsistent finishing by taking a lot of shots. If we follow their stripe down to the bottom left corner we find the opposite situation at Gateshead, who have created the fewest chances in the division but have been one of the most clinical sides, resulting in them scoring one more goal than Barrow so far.

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:

NL def eff 2015-12-21

 

Cheltenham lead the way defensively, having soaked up four more shots for each goal conceded than the average side while also allowing opponents around two fewer attempts.

In the opposite corner we see that both Torquay and Halifax have struggled defensively: allowing plenty of shots and struggling to keep them out. The latter are the division’s most porous side, having faced fewer than five shots for each goal conceded.

Interestingly, third-placed Eastleigh are the next leakiest, although they allow around half as many attempts at their goal (and the fewest in the division).

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:
NL exp 2015-12-21The sight of Grimsby lodged in the bottom right corner – even more dramatically than in the first graphic, to the point where I’ve had to move the label out of their way – suggests that the Mariners should be capable of challenging for the title.

Bromley‘s matches look ridiculously entertaining, with plenty of good goalscoring opportunities at both ends of the pitch. A quick look at the table confirms that they’re the fifth highest scorers and have the fourth most goals conceded, which seems to bear that out.

It’s interesting to see that Lincoln‘s attack is rated as the division’s best when we correct for shot quality, given that nine sides have scored more goals. Could they be capable of a concerted push into the play-offs with a bit more luck in front of goal?