Welcome. I hope this mini-series that Danny and I are producing will be informative and enlightening, as well as enjoyable reading. As always, if there are any questions or suggestions please comment below.
Why corners? Firstly, I wanted to write a piece on this topic as there is very little data and even fewer studies on corners and individual teams ability to score from them, and secondly I wanted to find out just how abnormally high Man United's goal scoring from corners actually is (11 goals in 19 games for Man United equals the record goals from corners from 38 games in 2010/11!).
So here goes.
Basic Numbers At the mid point of the 2012/13 season these are the raw numbers for corners in the Premier League:
|% chance of a goal
The % chance of a corner resulting in a goal is just 3.47%. Yet, we get so excited about corners!
Corners forced per game
This is the corners per game average chart.
Man City, Liverpool and Arsenal are the teams forcing a lot of corners. Stoke, Norwich and Sunderland are the teams who generate the least.
Can a high or low corner count be driven by possession of the football?
Corners with possession
The 4 teams who have generated the most corners through 19 games are the 4 teams with the highest possession %, but as soon as we move away from the top 4 possession % teams, the results become mixed. The bottom four possession % teams are not the 4 worst teams in terms of corners forced. In fact Reading and West ham are both forcing a good number of corners despite very poor possession totals.
We could refine the link between possession and corners if we used final third possession, alas, that is data I don't possess.
Goals From corners with corner scoring %
Corner data manually recorded, goals from corners comes from Squawka.com
Wow. Man United's goals scored from corners is incredibly high. 11 goals scored in just 19 games. The second placed team are Sunderland with 6. We move down the chart and find some very different teams in terms of talent level occupying the middle ground. Propping up the last few places are Arsenal, Norwich and Newcastle, teams who have nothing in common with each other in terms of possession, or height or quality of delivery.
As for the corner scoring %, Man United are clearly leading the pack and are a team who scores from 9% of their corners. This just seems like an incredibly high number, especially when viewed against the league average.
Expected Goals From Corners
Expectancy is calculated by taking the league total of goals from corners then dividing it by the league total of corners, which gives us 0.0347%, and re-applying that % to each teams individual corner count. Man United's 119 corners *0.0347 = 4.129 expected Man United goals from corners.
The bottom 8 sides in terms of goals scored from corners are all below their expectancy rate. West Brom and Sunderland, in 2nd and 3rd place, are exceeding their goals from corners expectancy by quite a distance.
Another way to look at the above chart is to view the teams in a positive or negative light in terms of expectancy.
Chelsea, Aston Villa and Reading are very close to their individual expectancy number. Newcastle and Norwich are a couple of goals down on their expectancy number and Sunderland are nearly 3 goals to the good.
No team has out performed or under performed their individual expectancy number by more than 3 goals over the first half of the season. No team except Man United.
Man United, with 11 PL goals from corners, are outperforming expectancy by a shade under 7 goals and that, frankly, is an incredibly good achievement. The question is why and how have Man united scored so many goals from corners?
Man United have 11 goals from corners and the 2nd placed team have 6, in short, Man united are nearly twice as good as the anyone in the rest of the PL.
Potential causes for Man United being so superior:
1) Delivery of corners Do Man United have better delivery than the rest of the league? RvP and Giggs are fine corner takers who hit the ball with pace and accuracy, but is their delivery twice as good as anyone else in the league? I would say no, every PL team has a player who is extremely skilled in set piece delivery.
2) Height I am assuming, and probably correctly, that the average height in the PL doesn't vary a whole lot. Yes, Stoke may be taller and Arsenal shorter, but Man United aren't a team of NBA giants nodding in RvP corners for fun.
3) Tactics This is the most likely cause of any of the four potential causes for United's ability to score form corners. But without positional data for the delivery placement of the ball and positional data for each United attacker it will be impossible to verify if Man United's superior tactics are the cause of all those goals. It is, though, unlikely that Man United employ a tactical set-up from corners that is twice as proficient than every other PL team.
Teams watch each other, catch up, pick up little tricks on how to score and how to prevent.
4) Opposition weakness Unlikely. We are now 19 games in to the season, everyone has played each other once.
In conclusion Man United's excellent goal scoring from corners may be down to a little extra height, a little superiority in delivery and tactics. But even if we assume a little superiority in all three categories it still doesn't explain a goals from corners total that is so superior to the rest.
Is the ability to score from corners luck driven considering how similar teams are in terms of delivery, tactics-zonal or man-marking- and height?
If I was forced to make a guess, I would say a decent portion of the ability to score from corners must be luck driven and a small part of it is delivery and the quality of crosses and attackers position placement.
Thanks for reading, I'll leave you with this
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