Friday, 27 January 2012

Individual Premiership Passing Stats Corrected for Difficulty or Why Leon Britton is Only the 66th Best Passing Midfielder.

When Alan Hudson returned to the top flight in 1983 for a swansong to his largely unfulfilled career,he again chose to swap the glamour of Chelsea for the bottle kilns of Stoke.A beautifully elegant passer in his prime,his biography was aptly titled "A Working Man's Ballet",he would have won more than the two England caps he gained during his first spell in the Potteries were it not for a spate of injuries and personality clashes.Stoke were a struggling (old) Division One side upon Huddy's re signing and while his return wasn't as epic an occasion as that of Sir Stan's a generation earlier it helped to stave off The Potters' descent into the lower reaches of the Football League.....for twelve months at least.

An abiding memory of Hudson at Stoke in that final season was of him casually taking the ball from the keeper,usually in front of the Boothen End before exchanging half a dozen square passes with various slightly terrified members of his own back four.It was only when an opposing forward was dispatched to chase the ball that Hudson stroked a forward pass into the vacated area,thus instigating a Stoke attack.This little cameo not only showcased  his skills,it also gradually allowed his team mates to become more comfortable in possession ,but as an unintentional by product it also ramped up the great man's passing statistics.Were Opta around thirty years ago Hudson would be near to the top of their passing charts.

More pertinently to the present,the scenario exposes some of the more obvious flaws of raw passing statistics.Square balls played under little or no pressure from the opposition are a lot easer to complete than forward passes played through the congested shipping lanes of midfield or the final third.Nowadays defenders are happy enough to play the Hudson role themselves and even avid long ball teams such as the present day Stoke are content to pass the ball along the backline,accruing possession gold stars as they go.Comparing the raw passing stats for a defender who can gain cheap successes with an attack orientated midfield player who is constantly trying to thread the eye will inevitably lead to misleading conclusion unless some attempt is made to contextualise each players passes.

In this post here I used the percentage of longballs a team plays as a proxy for the overall difficulty of the passes attempted and I've attempted something similar for individual players over last season and the first half of this one.This time I've used the percentage of forward passes from EPLIndex as the proxy for pass difficulty and I've grouped players by teams and split the sample as either defenders or midfielders.The profile of passes played by defenders and midfielders is very different,although defenders play proportionally more forward balls than do midfielders,62% compared to 50%,they are faced with many more safe,low risk passes.

How Defensive Pass Success Declines with Increased Proportion of Forward Passes.EPL.2010-12.

The correlation appears reasonably strong and an increase in forward passes leads to a decrease in successful passes,which is what you would expect.This allows us to derive a regression equation that can be used to predict a completion percentage for a certain proportion of forward passes based on the record of all defenders who played in the EPl over the last one and a half seasons.If we therefore calculate the completion rate expected for an average player for an actual player's proportion of forward passes,we can see if that actual player's completion rate is above or below our prediction.

For example Arsenal's Thomas Vermaelen  completed around 88% of his passes last season and those raw numbers rank him as equal 16th out of defenders who have played at least seasonal 100 passes over the two years.Vermaelen played 70% of his passes forward and from the regression we can say that an average defender would expect to complete just 68% of his passes under such circumstances.So the Arsenal defender was well above average for pass completion last term and if we repeat the calculation for all eligible defenders and re sort the rankings,he jumps to 7th best overall.

From the Vermaelen case we can see that the application of a reassessment of a defender's passing percentage based on the amount of forward passes he plays can re shuffle the pack and better reflect a player's enterprising passing style.The top ten defenders on raw passing completion percentages are listed below,followed by the ten biggest over achievers based on the predicted completion rate for an average defender making their percentage of forward passes.

Most Accurate Passing Defenders by Percentage Completion Rates.EPL 2010-12. 

Defender. Season. Pass
Accuracy %.
William Gallas. 2011/12 92
John Terry. 2011/12 91
Gary Monk. 2011/12 91
Ledley King. 2011/12 91
Johan Djourou. 2010/11 90
Alex. 2010/11 90
Jonny Evans. 2011/12 90
Kolo Toure. 2011/12 90
Ashley Cole. 2010/11 89
Vincent Kompany. 2011/12 89
Per Mertesacker. 2011/12 89

None of the most accurate raw passers appear in the corrected list below,although John Terry makes the first list from this season and the corrected list from the previous campaign.Clint Hill is by far the biggest beneficiary from the correction,jumping over 200 places on the back of an astonishingly large proportion of forward passes.Stoke defenders dominate the bottom 25 places in terms of raw stats,with Wilkinson,Shawcoss, Huth,Collins,Higginbotham and Wilson each making at least one appearance,but all move comfortably up the table under the revised terms.The EPL's worst corrected passer with at least 100 passes turns out to be Stoke's Ryan Shotton who falls over 30 places to the bottom of the pile compared to his raw stats,although in mitigation he hasn't been used exclusively as a defender.

Most Accurate Passing Defenders Corrected for Proportion of Forward Passes.EPL 2010-12. 

Defender. Season. Pass
Accuracy %.
Accuracy %.
John Terry. 2010/11 88 61
Wayne Bridge. 2010/11 78 59
Assou-Ekotto. 2010/11 71 54
Brede Hangeland. 2011/12 81 62
Nicky Shorey. 2011/12 76 59
Clint Hill. 2011/12 68 53
Th'mas Vermaelen 2010/11 88 68
Gael Clichy. 2010/11 80 62
Jose Enrique. 2012/12 80 62
Daniel Agger. 2010/11 76 61

If we now repeat the process for EPL midfielders we can similarly apply a correction to their  pass completion rates.The strength of the correlation is less strong on this occasion and the regression line is slightly distorted by the presence of the passing stats of the Big Five teams.Although passing rates are almost always attributed to the passer,it is self evident that there is also another player involved in the act of passing,namely the recipient.If we take Manchester City as an example,a pass from Silva to Aguero represents the nearly £70 million of combined talent,similarly Ya Ya Toure to Dzeko required a cash outlay of £60 million to bring about.The gap between the top and the rest of the EPL is never more evident than when you compare their respective attack and midfields.By contrast the average combined "cost" of a midtable EPL team's passing tandem will rarely peak at much more than £10 million and the average will be less.For example,Stoke's average midfield is worth around £4 million per player and it's regular strike force around 7 million.

In short the disparity between the Big Five and the rest is more evident when looking at passes originating from midfield compared to those originating from the defence.As with all high end improvements,small but noticeable improvements require a disproportionately large input of cash and in this case the presence of the stats of the hugely expensive top five team's midfielders weakens the correlation between difficulty of pass and pass completion for the league as a whole.

However,if we press on with this caveat in mind we see that Mikel and Denilson appear in both groups and the currently injured Lucas,despite his comparatively lowly completion rate can lay claim to being to top overall passer with 100 or more passes in each year because of his more adventurous attempts.

The much hyped Swansea midfielder,Britton slips from the top spot in the raw stats all the way down to 66th in the corrected version by virtue of his reluctance to pass the ball forward.

Most Accurate Passing Midfielders by Percentage Completion Rates.EPL 2010-12. 

Midfielder. Season. Pass
Accuracy %.
Leon Britton. 2011/12 93
SamirNasri. 2011/12 92
John Obi Mikel. 2011/12 92
Jake Livermore. 2011/12 92
Nigel de Jong.. 2011/12 92
Abou Diaby. 2010/11 91
Denilson. 2010/11 91
Paul Scholes. 2010/11 91
Mikel Artea. 2012/12 91
Joe Allen. 2011/12 90

Most Accurate Passing Midfielders Corrected for Proportion of Forward Passes.EPL 2010-12. 

Midfielder. Season. Pass
Accuracy %.
Accuracy % 
Danny Rose. 2010/11 79 63
Lucas Leiva. 2010/11 83 67
Denilson. 2010/11 91 73
Josh McEachran. 2010/11 91 73
John Obi Mikel. 2010/11 90 74
Alex Song. 2011/12 85 70
John Obi Mikel. 2011/12 92 76
Gareth Barry. 2011/12 87 71
Lucas Leiva. 2012/12 86 71
Michael Carrick. 2011/12 90 75


  1. Your Stat on passing the ball forward makes no sense when you refer to Leon Britton. He isn't really a play maker as he tends to disrupt the attack of the opposition. Therefore forward passes aren't always a viable option for him.

    Look at his other stats that back this up. Look how many assists he has had etc.... it is blatently obvious that his role in the team to stop the opposition and in doing so starts the attack even if it means not passing the ball forward.

    How can a player with a 93% passing rate be classed as the 66th best passer in the PL?

  2. Hi JD,it makes no sense to describe LB as the EPL's Xavi,which is what the media were doing mid season on the basis that their raw passing completion%'s were similar.
    Context.LB plays save,easy passes.nothing wrong with that,but it artificially inflates his %


    1. Excellent analysis. Although, I would wager that Xavi himself might not be much better than Leon Britton when his passing stats are corrected for forward play as majority of his or Scholes passes are sideways. I felt there was one thing that needs to be included in the model to improve the accuracy. Position of player when making a pass. I imagine making a forward pass is easier at the halfway line than it is playing right behind the striker. For example, Obi Mikel's stats are inflated by this as in 10-11 he was the pivot in Ancelotti's diamond and this made his natural pass availability a short forward pass. I am curious where Arteta was ranked after correction for forward passing.

  3. This is terrific and an overdue analysis Mark and I thoroughly applaud it. It begins to unlock the myth of total passes completed, which I suggest is a media/Sky Sport creation. It has a parallel with the nebulous "distance covered" stat that is screen produced after each game. Pity the No 10s in the world when they see that! As with most other elements of football, context is important in any analysis, including the position of the recipient. You have chosen a simple yardstick of forward passing; I suggest other variables could be added that could indicate the relative degree of difficulty - which begins to become an indicator of the skill level of the passer such as 1) pass distance (say generic measurements of <10m and <20m) 2) the passer being pressured or unpressured. Others could be added such as darkritual observes position of pass - again having a variable metric could be noteworthy. There is a case to be made too for calibre of the opposition eg a top 5 team vs a bottom 5 team, where you could expect elements such as space to play in was reduced the higher up you go.

    You would think this level of analysis is what coaches and scouts genuinely look for when they are making their money decisions - or I would hope they would be - when sourcing talent.