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Friday 30 March 2012

Predicting the Game's First Goal Scorer.

The importance and value of scoring the game's first goal has been well documented on this blog and elsewhere.Omar has written about the subject here and I have discussed the subject here and used illustrations from previous seasons to highlight how a team's final results are affected by the frequency with which they score first.If a team finds the net before it's opponent then they can begin to dictate the immediate course of the game.

In matches where the gap in quality between opponents is small,the first strike can greatly shift the balance of expectations.If we consider the case of two evenly matched sides then an opening goal from the the home team after half an hours play will shift the Expected Points total for that side from around 1.6 points to 2.3,a jump of 0.7 of a point.At the first whistle,the home side would have typically had about a 44% chance of ending the day with win bonuses all round,but by keeping out the visitors for 30 minutes before scoring themselves,they have increased the chance of a positive outcome to over 70%.Their visitors could have expected to average a tick over 1 goal per such encounter.But by failing to take their chances so far they would expect to average only 0.8 of a goal during the remainder of the game by the 30 minute mark and they trail by a goal as well.The afternoon is looking like it is turning into one of the more positive outcomes for the home side from the myriad of possible game scenarios.If we reverse the scoring and allow the visitors first blood,the importance remains.Their pre game win probability rises from 30% to 60% and their Expected Points rise from 1.15 to 2.05 points.

Even if we model the most extreme of mis matches that occur in the current EPL we see similar results.A relegation candidate taking an half hour lead at a title contender's home turf will see their win probability rise from 4% to 26% meaning the most likely result would still be a home win,but it's a massively improved situation compared to pre game.And the inferior team are now more likely than not to return with at least a point.

Scoring the first goal is therefore a good indicator of success on the day and if you look at the teams who have scored the highest proportion of first game goals so far they include most of this year's best teams.Both Manchester sides top the list,followed by Spurs,Chelsea,Newcastle and Arsenal.League stragglers such as Wigan,Wolves,Bolton,QPR and Fulham prop up the first scorer table.Therefore,it seems reasonable to assume that the typical rate at which teams register the first goal is related to their overall scoring record.You can demonstrate this relationship by plotting the proportion of match goals a team has scored over the season against the proportion of first goals each team has scored.

Seasonal Relationship Between Goals Scored and 1st Goals for EPL Teams 2009-11.


























A less general method involving a match by match basis,where the respective pre match goal expectancies are compared to the identity of the game's first goal scorer also yields a similar correlation.The line of best fit for two completed season's worth of EPL games also strongly indicates the near one to one relationship between the two.

Line of Best Fit for Proportion of Goals and First Goals Based on a Match by Match Samples.


























From a team perspective we are now in a position to predict the likely number of first goals a team of a given scoring and conceding ratio will record.We know that scoring first gives that team a much higher likelihood of winning the game than was the case at the start of the contest.In some cases a team will substantially exceeded or dip below those opening goal expectations and unless we can find compelling reasons for these first goal deviations,the most likely explanation is that the pattern has arisen because of small sample random chance.

So far this season Newcastle are the biggest overachievers in this category.They have scored the first goal in almost 70% of matches,yet they have scored barely over 50% of their game's goals.Their current position is a magnificent achievement,but some of it has probably been achieved through a fortuitous run of opening goals.At the other end of the table,Wolves with only 21% of opening goals despite scoring 32% of their game's goals can count themselves slightly unfortunate at the depth of their current plight.

We can move this kind of analysis a stage further by  looking at the level of individual players.Again the league's leading scorers tend to also top the first goal lists,indicating that a similar relationship exists at the individual level,namely the larger the proportion of goals you score then the more likely your are to notch an opening strike.There's a couple of tweaks needed before the player based data can be used.Firstly,players unlike teams don't play every game,so they shouldn't be penalised for occasions when they are absent and similarly they may enter the match after the first goal has been scored.For example RvP has featured in every EPL Arsenal game,but despite scoring a brace against Stoke he didn't leave the bench until the hour mark,by which time the score was already 1-1.So that game has to be discarded from the sample.

Secondly,position affords strikers more of an opportunity to open the scoring than say defenders.The average time of the first goal in the EPL is just after the 30th minute and this early in a contest defenders will still be prioritising defending.In a quick analysis consisting of the leading scorers from the last couple of years,leading strikers scored around 19% of their teams match goals,but accounted for over 21% of opening goals in those games.A line of best fit therefore can be plotted and used to predict the number of opening goals predominately attack minded players could be expected to score if we know or can estimate their likely scoring rate.

The Rate at which Attacking Players Opened the Scoring in 2011-12 in the EPL.

Player. Goals Scored
by Team.
Goals
Allowed by Team.
Goals Scored
by Player.
Number of
Games  by Player
Number of
1st Goals.
Predicted
Number of 1st Goals.
R van Persie 56 38 24 27 8 7.5
W Rooney 60 20 21 24 6 6.8
E Dzeko 35 12 12 13 4 3.6
S Aguero 63 25 15 19 6 3.8
C Dempsey 37 58 12 29 4 4.5
D Ba 33 35 16 23 5 5.9
Yakubu 32 40 13 19 4 3.9
G Bale 50 31 10 26 5 3.9
F Lampard 33 22 10 21 3 4.0
P Crouch 27 36 8 24 2 3.6

For the majority of the goal scorers listed their actual rate of opening goals is very close to their predicted levels.Aguero's tally of 6 is around 30% higher than you would expect from his overall scoring record and the record of Man City when he starts,while Rooney,Ba and Crouch each under perform compared to average expectations.However,we are dealing with very small totals here and any under or over performing trend should be deemed as much more likely to be descriptive as opposed to predictive.

Placing too much credence upon single season numbers may lead to teams and individuals being either over or under rated.A run of randomly superior rates of 1st goal scoring may falsely inflate a team's points total and may not be predictive or indicative of future levels of performance.This may have occurred in the case of Newcastle this year and of Ipswich here.Similarly,opening goals as we have seen are potentially valuable and players who manage a small sample sized glut of such strikes may appear to possess a valuable ability that may or may not exist.Players may be able to control to some degree the amount of goals they score in a season, it certainly is a reasonably repeatable skill across seasons.But the order and thus the importance in which these goals are scored during a game may be much more of a hostage to chance.

Tuesday 27 March 2012

Manchester City and United.A Tale of Two (Non) Penalties.

As the likely destination for the Premiership title heads towards it's climax and a possibly decisive derby meeting at the City of Manchester Stadium in late April,it's unsurprising that almost every contentious incident involved both Manchester teams are coming under scrutiny.

Penalties,along with goals are the lifeblood of football and while lacking the regularity of the latter,penalties compensate by posing numerous immediate questions.Was it a penalty,is there going to be a red card and will he score? to name just three.And it was penalties or in this case the lack of an award that provided the centre pieces for two moments of controversy in this week's game involving both City and United.


Manchester City have failed to beat Stoke City at the Britannia in the Premiership despite a handful of opportunities,a consistently superior side and the occasional helping hand from a referee's red card.Never the less,small sample sizes don't really change the underlying odds of a title chasing side beating a midtable drifter and so the blue side of Manchester were fairly substantial favourites to win on Saturday evening.However,the game ran the usual course of recent top flight encounters where City entertain City,as Stoke departed from their stifling defensive approach just long enough to provide a moment of pure brilliance and put their more expensive visitors on the back foot.This time it came from Crouch,who joined in with Pennant and Begovic's long range game of "keepy up" to smash a Greenhoff like volley past Joe Hart.The goal was rightly celebrated on MOTD2 where any comparisons to Ya Ya Toure's 30+yard deflected equaliser 15 minutes later were quietly shelved. 


Stoke City v Manchester City Game Graph.
























Scorers.
1-0,Crouch (emulates Greenhoff),59'
1-1,Y Toure,67'

There's a widely held belief that the better sides receive a disproportionately larger number of penalties than their less talented opponents and also that they are penalized less harshly.It's not actually the case,as this post here points out.Teams,over a large enough sample of games receive penalties in proportion to the amount of attacking they do and concede in proportion to the amount of defending.However,that doesn't mean that poor decisions aren't made and as luck would have it both Manchester clubs got lucky with penalties that weren't awarded against them this weekend.

Barry's characteristically robust challenge on Glenn Whelan felled the Irish midfielder long after the ball had gone,was clearly inside the box and was a routine foul and yellow card to most pundit's eyes.Had the penalty been given at such an early stage in the game,it would have been a sufficiently major incident to wipe out all of Man City's talent based superiority.If Stoke had gone on to score from the spot they would have become the favoured side to emerge from that game situation with more points than Man City over the long term.

Stoke would have found themselves in a much improved situation,although ironically not as good a situation as they actually found themselves in 45 minutes later following a bout of excellent defence and their centre forward's wonder strike.Barry for his part would have needed to tread warily if he had been correctly carded for the 16th minute challenge.He was actually carded 23 minutes later.

How an Early Penalty would have changed the Stoke City v Manchester City Game.



























Manchester United's Monday night graph against Fulham is singularly dull.United were of course big pre game favourites,Rooney' 42 nd minute strike confirmed that they were much more likely to win and their Expected Points tally spent all of the second have ticking gradually up towards 3 points.

Manchester United v Fulham Game Graph.

























Scorer.
1-0,Rooney,42'

As in the Man City game the drama came about because of a penalty that wasn't given.Even SAF conceded that Carrick's last minute challenge on Murphy was a spot kick,although he did manage to spin the incident by suggesting that the official was still feeling guilty because he hadn't given United a "stonewall" penalty earlier in the match.SAF at his brilliant best.Fulham manager,Martin Jol was less impressed with the official,even going as far as to suggest that his former player at Spurs should have seen red as well as conceding the penalty.

Of the two non penalties this one had the most potential to wrench the game in a different direction.The closeness of the game situation was similar to the Stoke/ManC encounter,but the lateness of the hour made it a high leverage situation.United's Expected Points would have tumbled all the way down from nearly 3 to just below 2 if Michael Oliver had pointed to the spot and it would have been barely above 1 if they had entered injury time all square following a successfully converted kick.

How a last minute Penalty would have changed Manchester United v Fulham.





If Mancini had been quietly thanking Howard Webb at quarter to six on a Saturday evening in the Potteries,he was most likely loudly lambasting Michael Oliver across Manchester at a quarter to ten on the following Monday night.

Sunday 25 March 2012

Liverpool's Failing Attack.

It should have been a perfect match.John W Henry's purchase of Liverpool football club could have led to the implementation of the kind of under valued asset buying that under pins the Moneyball concept.The Fenway Sports Group already owned the baseball franchise in Boston and had a direct line to the Brains Trust who had devised the Moneyball concept when they bought out the previous American owners of Liverpool,Hicks and Gillett.Within months they had removed the underperforming manager and installed Dalglish as first caretaker and then as the permanent boss.They also bought with them a war chest of cash that eclipsed all but the Premiership's massive spenders.

Dalglish for his part had assembled an expensive,but not excessively so Premiership winning team when unfashionable Blackburn Rovers had pipped Manchester United on the last day of the 1994/95 season.Rovers were built on an impressive goalscoring record,mainly provided by the twin striking force of Shearer and Sutton and a good but not great defence that allowed just under a goal a game.Dalglish of course was a striker in his playing days,so it was to be expected that he would pursue the attacking route that had served him well seventeen seasons previously at Blackburn.Of the £100+ million that he spent during the early months of his tenure,the vast majority of the cash was splashed on attacking and midfield options.The hoped for twin striking threat of Suarez and Carroll alone accounted for £60 million,Downing,paraded as a potential "Moneyball" buy came at the cost of £20 million and Adam,Henderson and Coates amounted to a further £30 million.

If we look at the goal scoring records of all teams sorted by finishing position,we see that better teams on average do score more goals per game than do poorer ones.It's a long,long time since Manchester City simultaneously topped the premier division's scoring charts and also found themselves relegated to the second tier.Nowadays,every top three finishing side since 1998 had amassed at least 1.5 goals a game.A fourth place shot a Champions League qualification was more forgiving of a team's attacking intent,with a third of such teams scoring less than 1.5 goals per game.So the idea that goals boost finishing position appears sound in theory.In practice the expensive implementation at Liverpool under Henry and Dalglish proved to be a massive disappointment.Liverpool's current 1.27 goals per game was the average return for a team finishing just inside the top ten and only Everton in 2004 managed a 4th place finish while being so lacking in front of goal.






Goals allowed show a similar expected trend when plotted against finishing position.The less goals per game you allow the higher up the table you tend to finish.The majority of top four finishers allow less than a goal a game,a couple even manage to breach the 0.5 goal per game barrier and none over the period got close to allowing more than a goal and a half a match.In this respect Liverpool can claim to have possessed a typical top four defence.Their record of allowing exactly one goal a game sits very well with the average record of third and fourth place finishers,a realistic target for a well resourced team who have decided to avoid getting into a chequebook duel with the league's three mega spenders.It also tallies quite well with their defensive record over the previous couple of years,indicating that a richness of defensive talent was already at the club.







We can now put the scoring and conceding requirements together in a plot of a team's goal difference and finishing spot.A goal difference of 0.75 or better has virtually guaranteed a top four finish,so Liverpool's current +0.2 goals per game is entirely consistent with their current lowly position.And it reiterates where the current underperformance lies.Even if the Reds defence performed at historically exceptional levels,the poor returns from the strikers would make a top for finish highly unlikely.A cursory examination of the causes of Liverpool's failure to threaten a Champions League spot lies squarely at the feet of that part of the team that has had almost all the money thrown at it.A most un Moneyball outcome.





























Having identified the problem,we can move on to see what kind of return Liverpool have enjoyed for their initial investment and we will start with the attacking side of the ball.I'll again use the concept of Expected Points to "value" each goal scored by the team upto and including their embarrassing defeat at QPR.EP is derived from the probability that a team will win or draw against their current opponents given the current score and time remaining and the change in EP from the moment just prior to the goal being scored and immediately after can be used to evaluate the worth of that goal.

The value of a goal is very context dependent.First goals consistently move a team's EP by reasonable amounts,whereas last minute strikes have much greater variation,either counting for very little in lopsided games or a great deal if the prior game state is close.

How Liverpool's Goalscorers Increased their Team's Expected Points.

Opponent.
1st Scorer
Min.
EPPre Goal.
EPPost Goal.
2nd Scorer.
Time.
EPPre
Goal.
EPPost
Goal.
3rd Scorer.
Time.
EPPre Goal.
EPPost
Goal.
Sunderland
Suarez,12
2.12
2.67
@Arsenal.
Ramsey(og)78
1.56
2.82
Suarez,90
2.91
3.00
Bolton
H'derson,15
2.26
2.75
Skrtel,52
2.76
2.96
Adam,53
2.96
3.00
@Stoke
@Spurs
Wolves
Johnson(og)11
2.35
2.80
Suarez,38
2.78
2.96
@Everton
Carroll,71
1.84
2.88
Suarez,82
2.91
3.00
ManU
Gerrard, 68
1.13
2.60
Norwich
Bellamy, 45
2.16
2.80
@WBA
Adam(p), 9
1.77
2.45
Carroll,45
2.51
2.82
Swansea
@Chelsea
Rodriguez,33
0.987
1.88
Johnson,87
1.03
2.65
ManC
Lescott(og),33
0.554
1.32
@Fulham
QPR
Suarez,47
2.14
2.79
@AVilla
Bellamy,11
1.82
2.50
Skrtel,15
2.50
2.85
@Wigan
Blackburn
Rodriguez,53
1.17
2.15
Newcastle
Bellamy,29
1.20
2.03
Bellamy,67
1.71
2.71
Gerrard,78
2.76
2.98
@ManC
Stoke
@Bolton
Bellamy, 37
0.43
1.04
@Wolves
Carroll,52
1.75
2.65
Bellamy,61
2.68
2.95
Kuyt,78
2.98
3.00
Spurs
@ManU
Suarez,80
0.016
0.17
Arsenal
K'cielnly,(og)23
1.71
2.46
@S'land
Everton
Gerrard, 34
1.83
2.57
Gerrard,51
2.60
2.92
Gerrard,90
3.00
3.00
@QPR
Coates,54
1.71
2.61
Kuyt,72
2.68
2.96

The change in EP post and pre a goal does a neat job of quantifying the value of each goal and a cumulative running EP total can also illustrate the player's goalscoring contribution over a season converted to a points expectation.However,frequency of opportunity isn't accounted for,so below I've included figures for goals scored and total EP generated per minute of player playing time.The numbers have been multiplied by 1000 to reduce the amount of potentially confusing decimal place zeros.The ideal player and candidate for a team's end of season awards would be one who generated high proportions of both goals per minute and EPs per minute.In short,lots of goals when the team needed them most.

At this point the analysis becomes more subjective,but I've arranged Liverpool's scorers in descending order of combined attainment in each category.Craig Bellamy's goals were relatively frequent,for Liverpool at least and relatively important.He scored a couple of game opening goals and as Omar points out here in his 5 added Minutes Blog,opening goals are almost always significant strikes and he scored important goals against Newcastle and sealed victory at Wolves.Rodriguez didn't score frequently enough to topple Liverpool's free transfer and Gerrard's higher strike rate was dilute by his insistence in claiming a hat trick in the derby game.

It's only when we reach midtable that the big money men begin to appear.Suarez,like Bellamy opened the game's scoring twice,but he also claimed three low value closing goals,while Carroll was generally unproductive.Downing has yet to score outside of the Cup runs and Henderson hasn't scored since the opening phase of the campaign.

It's probably worth pointing out that these numbers are primarily descriptive as opposed to predictive,the sample sizes are too small in any case.They indicate how the points were won,but can't claim to predict how they will continue to be won.However,much in football revolves around how players and managers are perceived by employers and fans and the longer a big money star appears to under perform,then the shorter the leash becomes.Henry apparently envisaged an initially large outlay would be followed by a self sustaining period where Champions League money would flow into the club and that won't happen next year.

Summary of the Worth of Each Goal Scored by Liverpool Players in 2011/12 so far.

Player. No. of  Goals. Total EP. EP per Goal. EP per Minute.
(x 1000)
Goals per Minute
(x 1000)
C Bellamy 6 4.01 0.67 4.44 6.63
M Rodriguez 2 1.87 0.94 4.67 4.99
S Gerrard 5 2.75 0.55 3.21 5.83
S Coates 1 0.90 0.90 3.00 3.34
A Carroll 3 2.32 0.77 1.58 2.05
L Suarez 6 1.72 0.29 0.89 3.10
Own Goals 4 3.23 0.81 1.18 1.46
G Johnson 1 1.62 1.62 1.05 0.65
C Adam 2 0.72 0.36 0.33 0.92
D Kuyt 2 0.30 0.15 0.18 1.22
M Skrtel 2 0.55 0.28 0.23 0.85
J Henderson 1 0.50 0.50 0.24 0.49

For completeness I've added the decline in Liverpool's in game Expected Points caused by the goals they conceded.A good team with a poor defence often presents it's strikers with the opportunity to score high value goals by keeping the games close.If the situation is reversed and a poor attack fails to put distance between their team and their opponents,the defence can find itself conceding numerous high cost goals and that appears to have occured in the case of Liverpool.Although they allowed few goals,they were invariably first game goals or late winners and the increasing number of second and third goals that are now being scored implies that the effort may be taking it's toll.

How Goals Conceded by Liverpool Decreased their Expected Points. 

Opponent. 1st Scorer.
Min.
EP Pre Goal. EP
Post Goal.
2nd Scorer.
Time.
EP Pre
Goal.
EP Post
Goal.
3rd Scorer.
Time
EP Pre Goal. EP Post
Goal.
Sunderland Larsson,57 2.70 1.81
@Arsenal.
Bolton Klasnic,90 3.00 3.00
@Stoke Walters(p),21 1.54 0.76
@Spurs* Modric,7 1.36 0.66 Defoe,66 0.10 0.01 Adebayor,68,90 0.00 0.00
Wolves Fletcher,49 2.97 2.78
@Everton
ManU Hernandez,81 2.60 1.16
Norwich Holt,60 2.81 2.03
@WBA
Swansea
@Chelsea Sturridge,55 1.71 0.95
ManC Kompany,31 1.29 0.63
@Fulham Dempsey,850.97 0.10
QPR
@AVilla
@Wigan
Blackburn Adam(og),452.26 1.37
Newcastle Agger(og),25 2.06 1.20
@ManC Aguero,10 0.99 0.39 YaYa,33 0.35 0.09 Milner,75 0.08 0.01
Stoke
@Bolton Davies,3 2.07 1.33 RCoker,29 1.12 0.50 Steinsson,50 0.89 0.32
@Wolves
Spurs
@ManU Rooney,47 0.97 0.298 Rooney,50 0.29 0.06
Arsenal vanPersie,31 2.47 1.66 vanPersie,91 1.13 0.11
@S'land Bentdner,56 1.54 0.60
Everton
@QPR Derry,77 2.98 2.74 Cisse,86 2.83 1.30 Mackie,91 1.15 0.12

*Adebayor's 2 goals have been compressed into one column.By the time they arrived Liverpool were 2 goals down and a similar number of players down on the pitch as a result of red cards.

In the next part,we'll look at the kind of statistics that might have encouraged the Liverpool Group to invest substantial sums on the players they did,how predictive and sustainable between seasons those stats are and how successful were their in game substitutions.

For a fascinating look at how the Red's season has been affected by penalty kicks check out Omar again here.

Tuesday 20 March 2012

The EPL's Best Defenders so far,2011/12.

Using the methodology in this post here,I've listed the most impressive defenders from each EPL side so far this season.It would appear that the more times a defence loses a ground based duel,the more goals they are likely to concede.Therefore a defender who contests more ground duels than the average for his team and who can also lose less than the average number of such duels compared to the average for his side could be considered his team's outstanding defender.The players listed below are either above average in both categories (denoted by ratios in excess of 1) or are slightly below average in one category,but overwhelmingly dominant in another.For example Koscielny contests more ground duels than has been the average for Arsenal defenders so far this year and had lost less than the average of such contests.By contrast Rio Ferdinand has contested a below average number of ground duels,but has been imperious when doing so.

The Outstanding Defenders from Each EPL Team based on Ground Duels Contested and Lost.

Player Team Total
Ground Duels Ratio.
Ground
Duels Lost Ratio.
L Koscielny Arsenal 1.08 1.04
C Cuellar Aston Villa 1.10 0.97
C Samba Blackburn 1.01 1.20
Z Knight Bolton 0.73 1.91
B Ivanovic Chelsea 1.12 1.34
P Jagielka Everton 0.91 1.82
B Hangeland Fulham 1.11 1.05
M Skrtel Liverpool 0.83 1.56
V Kompany Man City 0.76 1.70
R Ferdinand Man Utd 0.57 2.66
S Taylor Newcastle 0.71 1.82
L Barnett Norwich 1.12 1.02
C Hill QPR 0.86 1.33
Y Kaboul Spurs 1.16 1.19
R Huth Stoke 0.95 1.25
P Bardsley Sunderland 1.03 1.03
S Caulker Swansea 0.90 1.36
G McAuley WBA 1.20 1.23
M Figueroa Wigan 1.17 1.04
C Berra Wolves 1.07 1.04

Evaluating EPL Defenders.

The attributes of attacking players in whichever sport are usually easier to quantify than those of defenders.Individual stats such as shots,shots on target are readily available and are strongly correlated to goals scored,which in turn correlate with team success. Therefore,there is a credible chain running from onfield actions of strikers through to the eventual success of his team and this allows us to begin to attach numerical estimations to that strikers contribution.

In the case of defenders the correlations are much less clear cut.We can reasonably suggest that a successful tackle or interception made by a defender is a good thing for his side,but these positive actions don't accumulate positive results,such as goals.Instead they prevent unwanted occurrences such as goals conceded.And it's plain that counting up goals scored (in the case of strikers) is much easier and more accurate than counting goals prevented (in the case of defenders).Quantifying something that has happened is always preferable to quantifying something that hasn't.

If we want to be able to evaluate defenders in a similar way to strikers,we need to be able to correlate their on field actions to events that contribute intrinsically to the final result.And an obvious way to do this is to see which defenders are "best" at doing things that correlate well with how often a team concedes a goal.We are beginning to have access to much more extensive player data especially in the EPL and statistics such as tackles lost,ground duels lost and aerial duels are just three of the likely candidates that could correlate to goals allowed by a defence as a whole.

Of the three,ground duels lost by defenders has the strongest correlation to goals allowed by a team and the relationship is in the expected direction.The shorter the time between defenders losing out during a ground duel,then the more goals their team can expect to concede on average.To take an example of extremes,Hull's defenders were beaten during ground duels once every 22 minutes,that's about 17 times a game for a back four and they allowed almost 1.7 goals a game.While by contrast Liverpool's defenders were beaten once every half hour or 12 times a game and allowed just 0.7 goals per game.

These numbers are of course a broad brush description of a Saturday afternoon.Not all duels lost by defenders will be lost in a defensive context,although the majority will be and not all defensive ground duels will be lost by defenders.Hopefully though there is enough integrity in the numbers for the conclusions that losing ground duels is bad for a team to be valid and therefore a defender who can minimize the amount of such contests he loses is a prized asset.However,before we can move to a player by player analysis we need to process the player statistics.



 Playing time will impact on the amount of duels a defender loses(if you're not on the pitch,you can't be beaten in a one on one),so I've allowed for actual playing time,including substitutions when calculating how often a defender is beaten.Secondly,I've allowed for the quality of the team in which a player is performing.I'd imagine it's easier being a defender for ManU than it is being on for Bolton where the amount of attacks you are likely to have to defend will be greater.If a defender is losing three ground duels a game in a team who are as a whole losing 20,then the probability is that he may be a better defender than someone who is also losing three duels,but in a side who concede only 10 such "defeats" a game.Thirdly,hindsight is a powerful tool,so I've listed the best defenders of ground duels from each EPL side from the 2008/09 season and shown where they are now.This should allow us to decide if the view of their defensive abilities based on this statistic in 2008/09 were vindicated by future events.

The overall defensive rating for ground duels comprises two ratios.the Total Ground Duels Ratio is derived from how often a defensive player is engaged in a ground duel compared to the average for him and all other defenders from his side.A figure in excess of 1 indicates that the player is engaged in more often in such contests than is usual for defenders from his side.This indicates how often a player is involved in crucial in game events compared to his team's norm.

The second part of the rating is the Ground Duels Lost ratio.This is simply the time between ground duel defeats for the player divided by the average time for him and his team mates.So again a figure in excess of 1 indicates that the player is of above average efficiency at avoiding defeat in ground duels compared to his team mates.

These are the 20 best defenders,one from each team from the 2008/09 EPL season.Ideally you would like your player to be involved in above average numbers of challenges and be of above average efficiency during those challenges.Fulham's Hangeland stands out on that basis,but unsurprising names such as Vidic,Cahill,Distin,Givet and Turner would appear to be exceptional contestants in one on one contests.

Best Defenders at Dealing with Ground Duels for each EPL Team 2008/09.

Player. Team in 2008/09. Total Ground
Duels Ratio.
Ground Duels
Lost Ratio
Current Situation.
G. Clichy. Arsenal. 1.31 0.82 Sold to ManC for £7 million.
M Laursen. A Villa. 1.55 0.80 Retired due to injury.Villa "legend."
G Givet. Blackburn. 0.67 2.57 Blackburn regular.
G Cahill. Bolton. 0.91 1.41 Sold to Chelsea for £7 million.
B Ivanovic. Chelsea. 0.96 1.29 Chelsea regular.
J Yobo. Everton. 1.06 1.18 On loan at Fenerbahce.
B Hangeland. Fulham. 1.19 1.17 Fulham regular.
M Turner. Hull. 0.83 1.46 Sold to Sunderland for £6 million.
J Carragher. Liverpool. 0.81 1.55 Still a Liverpool player.
N Onuoha. ManC. 0.78 1.40 Loaned to S'land.Sold to QPR for £3 million.
N Vidic. ManU. 0.99 1.42 Man U captain.
D Wheater. Middlesbro' 0.95 1.25 Signed for Bolton in 2011 window.
S Bassong. Newcastle. 1.14 1.15 Sold to Spurs for £8 million.On loan at Wolves.
S Distin. Portsmouth. 0.79 1.83 Sold to Everton for £5 million.
A Faye. Stoke. 1.08 1.08 Stoke player of year,now at WHU.
P Chimbonda. Sunderland. 0.98 1.10 In Championship for Doncaster via Blackburn and QPR.
M Dawson. Spurs. 1.24 0.94 Still at Spurs.
L Barnett. WBA. 0.93 1.43 Playing for Norwich in EPL.
M Upson. WHU. 0.85 1.37 Stoke squad player.
M Figueroa. Wigan. 1.02 1.05 Wigan regular.

The majority of the players are still playing at the highest level of competition and where they have dropped in class,age or injury are possible secondary factors.Four of the five defenders who were transferred for big money were rated well above the average of their team mates in terms of avoiding defeat during ground contested duels,although not necessarily in terms of the number of ground duels contested.This could indicate that good one on one strength is valued in the EPL along with the ability to organise others to do some of your work for you.

It's also worth noting that some of the worst defences can contain some of the best defenders and this could explain why defenders are generally worth much less than strikers.A subject touched upon here.An outstanding forward will probably produce goals because his team can chose to provide him with the majority of the chances.By contrast an outstanding defender may simply be forced to watch as his less talented defensive colleagues are picked on by the opposition.Buying a forward may guarantee goals,but buying a defender may mean you need to buy one or two others before the expected improvement materializes and it opens up the possibility of investigating if four average defenders produce better defence than two outstanding ones and two below average ones.Is a defence as good as it's weakest link?

The majority of the players listed have proved to be above average defenders over the ensuing two and a half seasons,indicating the likely value of these kind of statistics,so in  a future post I'll post up this season's ground duel leading defenders.