Scatter graphics: League 2, 2015/16 season
Now that the “regular season” is over in League 2, here are the final set of scatter graphics. These compare the attacking and defensive performance of each club: they are explained here if you haven’t seen them before and the previous instalment is here.
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).
Accrington can consider themselves unfortunate to have missed out on automatic promotion as they were the most dominant side in the division overall. Nobody took more shots and only Portsmouth allowed fewer.
Interestingly the only member of the final top seven not to be sat in the dominant bottom right corner are champions Northampton, who created a relatively average number of chances. The next two charts will shed some light on this.
In the opposite (top left) corner we can see that the two relegated sides, Dag & Red and York, spent the most time on the back foot this season. While Yeovil took fewer shots than either of these two, the Glovers were a lot more organised in defence.
Both Notts County and Carlisle saw plenty of action at both ends – so it’s perhaps unsurprising that their two encounters this season generated eight goals – while Wycombe‘s matches were relatively quiet.
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:
We can see that while Plymouth and Accrington both created plenty of chances, Oxford and Bristol Rovers – who achieved automatic promotion at their expense – were more ruthless at turning shots into goals.
After those four clubs, it’s perhaps a surprise that the next most industrious shooters were Notts County. However with only Newport requiring more attempts to find the net on average, the Magpies were unable to make those opportunities count.
We saw above that Northampton won the title despite taking a relatively modest number of shots, and here we can see how ruthless they were at turning them into goals. Barnet and Morecambe also made the most of the chances they took.
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:
Northampton also look good on the defensive picture: they’re among a cluster of clubs in the top left who made it very difficult for opponents to shoot and score against them. Despite looking poor on the previous chart, Wycombe had their defence to thank for a season spent largely in the top half of the table.
We saw on the previous graphic that Morecambe have been sharp in front of goal this season, but they’ve made their opponents look even more clinical; nobody soaked up fewer shots for each goal conceded.
Portsmouth allowed impressively few attempts at their goal, with Accrington the only other side to have permitted fewer than eight per match on average. While Leyton Orient were similarly restrictive, allowing the fifth fewest, they were the third worst at keeping shots out of their net.
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:
When we correct for shot quality, Accrington still look as impressive as Oxford and it’ll be heartbreaking for them if they don’t prevail in the play-offs.
Again we find York and Dag & Red in the undesirable top left, so unfortunately it looks as though their relegations were largely warranted. Yeovil‘s performances were the next worst overall, but their defence looks to have compensated for their poor attack (as their run of eight clean sheets from nine matches earlier this year testifies).
Northampton are a lot further over to the right when we factor in shot quality, suggesting that they were very picky about the shots they took and excelled at getting the ball into good goalscoring positions before letting fly.
Note: it’s my aim to expand on this with a club-by-club review of the season for all three Football League divisions (and the National League if I get time) in the coming weeks.