Friday, December 5, 2014

Introducing EPL Effect Size Index

Effect Size Index (ESI) tracks how well a team performs when a player is on the park, as opposed to their scoring/concession rates when he is not. 

A player who plays every minute of every contest for his club - usually a goalkeeper or centre-back, will have an ESI of 0.000, as this statistic charts the difference between the team's performance when a player is on the pitch (in terms of frequency of goals scored/conceded) and compares it to his club's overall rates of goals scored/conceded. Thus, a player who plays every minute of the season - or who's Individual Plus/Minus per 90 minute matches that of his club - has an ESI of 0.

Take, for example, Jack Wilshere (please). Arsenal score less frequently when he is on the pitch, while conceding more often: Arsenal have GD this season of +7, but while Wilshere has been on the pitch the Gunners have been outscored by a total of 10 goals to 4 (making Wilshere's +/- a poor -6). While this might be bad luck, bad teammates or bad Jack, and keeping in mind that 0.000 is for want of a better word "baseline", his ESI is a phenomenally bad -1.527.

You can find the ESI of every player who has managed 450 minutes on the pitch this season by clicking this link. Player are grouped by position, and arranged in order of best to worst ESI.

Tuesday, November 11, 2014

On the impact of Bobby Zamora, Eduardo Vargas and Richard Dunne at QPR

The thoroughly entertaining Iain Macintosh today compiled an article suggesting how well QPR have been performing recently. He credits much of this resurgence to Harry Redknapp's re-utilisation of two senior Rangers, Bobby Zamora and Richard Dunne.

While he is of course correct - especially in a poetic sense - a certain set of numbers emerging from my ever-expanding Player Plus/Minus dataset - which you can find by clicking here - might help quantify the effect Zamora and Dunne have both have on the Hoops.

In their eleven matches so far, the Rs have managed a goal difference of -11, or being outscored by one goal for every 90 minutes they take the field. This means any player who has managed each of the 990 minutes Rangers played so far this season will have an Individual Plus/Minus of -11. If you will, think of Individual Plus/Minus as a player's "personal" goal difference, or the amount of goals his team concedes while he's on the field, subtracted from those his team scores when he plays.

However, players rarely play every minute of every match of the Premier League season - in fact, in last year's abbreviated (four-team) sample, only Brad Guzan and Steven Caulker managed such a feat. This means to compare a player to his teammates and thereby examine his impact on his club, we must standardize the time-frame in which player and team both score and concede. That is, a team's Goal Difference divided by 38 results in the average amount they score/concede more than their opponents per match - so a Player's Plus/Minus rating per 90 minutes allows us to compare a team's performance when a certain player is deployed against when he is not.

But technical definitions aside, this set of information details how much a team scores or concedes over 90 minutes when a player is on the field. And Zamora's, particularly, numbers are spectacular. When he is on the field, QPR have a Goal Difference per game of 0, a full goal-per-game improved over when he doesn't take the park. 

This is the single best "Impact Factor" for a forward in the league, and is shared (with teammate Yun Suk-Young) for the third-best rating of any position. Only Jack Cork and Charles N'Zogbia are better throughout the entire league; another Ranger with a similarly lofty total is forward Eduardo Vargas, whose Impact rating of +0.803 is fifth-best.

Dunne, the other cartworkhorse whose virtues Macintosh espouses, rates as the seventeenth-most impactful defender in the league of the 95 that qualified (must have played at least 360 minutes).

Other interesting points to come out of the data set include Adnan Januzaj's lack of ability to influence proceedings for Manchester United (with the Reds 0.71 goals per 90 minutes worse off with him on the field), Jack Wilshere's awful start to the campaign (Arsenal are nearly 1.7 goals worse-off with him playing, the worst ratio in the EPL) and the absolute ostrich egg laid by France forward Emmanuel Riviere.

For more information - and some pretty, relatively-informative charts - on Player Plus/Minus, you can read the primer here, or search this site for "Plus/Minus".

Thursday, October 30, 2014

The Decline and Fall of the Caribbean Empire

Throughout recorded human history, there exists a circular nature to the rise and fall of the great or powerful civilisations. This can be thought of as a series of stages, listed below, that describes the path each major power takes in their rise to supremacy and eventual ruin.

From bondage to spiritual faith
From spiritual faith to great courage
From great courage to strength
From strength to liberty
From liberty to abundance
From abundance to leisure
For leisure to selfishness
From selfishness to complacency
From complacency to apathy
From apathy to dependency
From dependency to weakness
From weakness to bondage

For the Roman Empire, the cycle took somewhere - if you use the same death rattle as Gibbon - a little over five hundred years. For the West Indies, a complete circle looks likely to be complete in less than fifty.

Thursday, October 9, 2014

On Pietersen, again.

"Relationships don't work the way they do on television and in the movies. Will they, won't they, and then they finally do and they're happy forever. Gimme a break. Nine out of ten of 'em end because they weren't right for each other to begin with and half the ones that get married get divorced anyway and I'm telling you right now through all this stuff I have not become a cynic - I haven't ... Bottom line, couples who are truly right for each other wade through the same crap as everybody else but the big difference is they don't let it take them down. One of those two people will stand up and fight for that relationship every time".

I used to really like Scrubs, back when it was as about an accurate representation of a hospital as has ever been shown regularly on US television. (And when the writing/overarching plots didn't stink, so, if you're counting that's about to the end of Season 3). While being funny in many different ways, it also had the uncanny ability to drop truth bombs like a veritaserum-charged cluster weapon. The quote above from Dr. Cox is one of my favourites.

Ten years ago, Kevin Pietersen and the England and Wales Cricket Board decided to commit to one another in a very real - and legally binding - sense. Ten years' shared property and escalating spats over which account pays which bill dutifully followed. When each party could complain to their mates about the other no longer, we all got to experience thee long-expected divorce, one in which the ECB retained sole custody of Alastair Cook and Pietersen kept the loyal-but-crazy family terrier.

Both went into this star-cross'd tryst expecting the other to mellow in response to their charms. Neither ever truly appreciated just how far apart they were on some - or indeed most - issues.

The pair fell out once and for all because they just weren't right for each other in the first place. Pietersen was always too outgoing/free-spirited/much of a wanker for a cricket board renowned for conservatism, uniformity and unleashing Chris Tavare on the world. As much as they may have spooned in public early on, their romance was almost certainly due to end poorly: the ECB wished Pietersen would curtail his silvertail tendencies, while the player just wanted his hem-hawing spouse to get off his back and let him be the man they fell in love with. 

Thirteen or so years after Dr. Cox indirectly predicted it, when each side felt they had compromised enough, neither was willing to take the first step towards reconciliation and risk losing face.

Love disappeared long ago, probably when each side realised they couldn't change the other enough to tolerate coexistence; nor was it worth anyone's time trying. Pietersen and England weren't right for each other in the first place, but mutual success made them (temporarily) brush aside most major concerns until there was simply too much detritus surrounding them.

The ECB will move on, and likely marry someone not quite so ostentatious, less of a good-time guy - but still someone who might have the talent to average 40 or 45 at Test level. Like his buddy Shane Warne, Pietersen will be seen with every flash young thing able to provide him with an ego boost and a quick cheque, starting with the Delhi Daredevils and the Melbourne Stars. 

The accounts are separate and the kids are starting to get to know Mum's new "friend", Gary. But the offspring of this flawed marriage won't ever forget the good times. 

Tuesday, September 30, 2014

Thursday, September 18, 2014

2014-15 EPL individual player plus/minus

Interested in which player contributes the most - or the least - to your favourite club's wins or losses? You can find out by checking out the 2014-15 EPL individual plus/minus stat pages.

You can also access this information via the Room of Informational Illusions.

(Suggested reading: A Plus/Minus Glossary).

Tuesday, August 5, 2014

What the numbers said: Cardiff City 2013-14

The following analysis was performed utilizing data from the Individual Plus/Minus series published on the site throughout the year. You can find the full data set in the Room of Informational Illusions.

Should you wish for a glossary of terms used in this article, it can be found here.


Cardiff City didn’t have a great 2014. After an encouraging start, the Bluebirds tailed away almost at the precise the instant owner Vincent Tan began questioning manager Malky Mackay’s job security. When Mackay was replaced by Ole Gunnar Solskjaer, the new manager began rotating their first team and team structure at an alarming rate – with the results you’d expect.

Some players didn’t suffer from their Welsh association. The two players for whom Cardiff City broke their transfer record in 2013 (Gary Medel and Steve Caulker) were perhaps the club’s best players, while two loyal Mackay men – David Marshall and Fraizer Campbell – had seasons that have or still might win them moves back up to the Premiership.