In the next installment of "what happened last season in the Premier League?", here are season totals on teams' defensive prowess. Much has been made of Arsenal's inability to defend well and its need to improve defense during this transfer window. But the numbers tell a slightly different story - at least in part. Turns out, Arsenal conceded the fewest shots overall last year and the fewest accurate shots - so in overall numbers they did best - while Manchester United defended most effectively on an accurate shot to shot basis. Where Arsenal did less well and came in 13th in the league is in the ratio of accurate shot conceded to overall shots conceded.
But first things first. As the first two graphs show, the teams that struggled also had the leakiest defenses last year in terms of total number of shots conceded. Teams that defended surprisingly well in terms of overall shots were Wigan (yes, I know, Wigan again), as well as Liverpool and Newcastle.
One notable surprise among the teams playing very effective defense, as indicated by the ratio of shots on target to overall shots: Fulham; the Cottagers came in 4th in the league in degrading opponents' accuracy. One notable surprise at the lower end of the next graph: Chelsea whose ability to degrade opponents' accuracy ranked between Villa and Stoke. And while Liverpool made big news with the signings of Carroll and Suarez, their defense ended up being highly effective last season (and perhaps getting less well-deserved attention).
To me, both pieces of information - total shots and shot ratios - are important. Total shots tells us something about the teams' ability to keep opponents away from their goals, so this is information that indicates the overall team effort (including midfield or even strikers' ability to press). Shot ratios are more direct measures of defensive performance - not letting opponents get good shots off when they are near enough to the goal.
But these are all relative judgments - after all, Arsenal still ended up in the quadrant of teams that conceded relatively few shots and few goals, as the next graph makes clear. So while they did better than the teams that finished ahead of them in terms of shots conceded, they conceded a higher percentage of goals on those shots.
But first things first. As the first two graphs show, the teams that struggled also had the leakiest defenses last year in terms of total number of shots conceded. Teams that defended surprisingly well in terms of overall shots were Wigan (yes, I know, Wigan again), as well as Liverpool and Newcastle.
Most of the data for other teams should not come as a real surprise to anyone, but it's interesting to see the totals nonetheless. I'll also note a few interesting exceptions.
But these are all relative judgments - after all, Arsenal still ended up in the quadrant of teams that conceded relatively few shots and few goals, as the next graph makes clear. So while they did better than the teams that finished ahead of them in terms of shots conceded, they conceded a higher percentage of goals on those shots.
More season totals on all the big leagues to come soon. Stay tuned.
