Friday, November 30, 2012

The Myth of the English Premium

Every time an Andy Carroll or Alan Shearer get sold, Liverpool (over-)pay for British-born players, or Arsene Wenger (and lately, Alan Pardew) go shopping for undervalued talent in France, the idea of an English (or sometimes, British) premium is bandied about.

But is it really true that you have to pay a premium for English players? The underlying idea here is that there is positive discrimination in the English player market, with selling clubs charging a little (or a lot) extra for English or British players.

To find out, first, let's look at how the transfer market currently values English v. non-English players (or players fortunate to hail from the British Isles or not).

Using data from the respected Transfermarkt website on all players currently on Premier League squads, we performed a variety of calculations on their transfer values (complete data were available for a total of 502 players; we collected these data in October).

One thorny problem, of course, is who counts as "English" or "British" - this turns out to be slightly less than obvious. Sure, Ben Foster is English, but there are a number of players whose ancestry or personal history is more than a bit muddled. Some of it owes to the vagaries of modern migration; some of it has to do with which national side someone chooses (or hopes) to play for. So, this is a long way of saying: we did our best to determine a player's nationality, but we probably made a few calls that are debatable. That's our first indication, though, that determining the English premium is less than completely straightforward.

Keeping those caveats in mind, the numbers show that the market appears to value English and British (which includes Scottish, Irish, and Welsh) players less than the average.

Recall from our previous analysis that the average Premier League player this fall is valued at £5.94 million. In contrast, English players are valued almost exactly one million pounds less (£4.96) and all British players combined about £1.5 mio. pounds less. (£4.51). In fact, given that about half of all players in the league qualify as British in some way, the average of £5.94 million is brought down by the relatively low valuations of native footballers. The average for non-Brits, in fact, stands at £7.39 million.

On its face, this suggests that English/British players can be had at a bargain, rather than a premium.

But seeing differences in averages doesn't mean that English or British players necessarily command a premium - by definition, "premium" implies that a club needs to pay more to obtain an English player than they would for an ordinary player; it's a kind of surcharge for the same player they would otherwise buy.

Wednesday, November 28, 2012

Mapping the Market: How Much Do Players in the Premier League Cost?

If you wanted to buy yourself a Premier League footballer, how much would you have to shell out?  As we get closer to the January transfer window, we thought it would be interesting to take a fresh look at how much players go for these days.

To find out, we collected data from the respected Transfermarkt website on all players currently on Premier League squads and performed a variety of calculations on their transfer values (complete data were available for a total of 502 players; we collected these data in October).

The average Premier League player is currently valued at £5.94 million - a tidy sum to be sure, and of course higher than it's ever been, but not stratospheric. The interesting thing, too, is that the values of players aren't normally distributed - in bell curve fashion, where most (average) players would be expected to be located somewhere in the middle, and then a few on the low and the high ends, respectively. Instead, the transfer values of players show a remarkably skew toward the lower end. Take a look.

Here's the overall distribution (we've grouped players in bands to make the graph more intelligible).

Clearly, the majority of players are valued at significantly less than the average. 25.9% are on the market for £1.3 mio. or less, 51.6% are valued at £3.1 mio. or less, and a whopping 70.5% are valued at £5.7 mio. or less. This makes sense - many of the players in the dataset (in fact, by definition about half, in a squad of 25, assuming some injuries over the season) are not regular starters for their clubs. And of course there are a few very special talents who can command much, much more, thus bringing up the average.

Finally, we wanted to see how much the market differentiates by position. Here we see that the market values different positions differently - something we've long known, but seldom have put a real number on. Players' values increase significantly as we move up the pitch, with forwards valued highest at an average of £7.6 mio., and net minders at less than half that (£3.3 mio.) The jumps in value from keeper to defender is almost £2 million, midfielders are about £1 mio. more than defenders, and strikers about £1.4 more valuable than midfielders.

The market appears to value scoring goals more than it values preventing them.

Of course, these broad averages obscure a lot of differences across individual players and clubs - something we will be writing about in the coming weeks - but they map out the domestic English market as it stands today. 

Wednesday, November 14, 2012

Back To Basics: Who Touches The Ball?

The ball is round, Sepp Herberger, the legendary, World Cup-winning coach of the 1954 West German side used to say. Moving the leather around the pitch is what football is all about. While that's always been true, how teams have gone about maneuvering the ball into their opponent's net and away from their own has changed considerably since Herberger's days, however.

In this day and age, it is hard to imagine teams playing a 2-3-5, the most common formation in the early days of the game. Instead, as Jonathan Wilson has described so beautifully in his magisterial history of football tactics, Inverting The Pyramid, football has evolved to become a game focused mostly on offense to a game focused on balancing offensive and defensive needs. Today, with the rise of the false 9, Barcelona and Spain are even occasionally playing without a striker, period.

So who touches the ball in the modern game? Is the tactical focus on a balance between offense and defense reflected in the match data?

To see if it is, we calculated which positions actually see more and which see less of the ball with the help of Opta Sports match data for a recent season of Premier League play (2010/11). Our original intuition was that the balance between offense and defense should mean that midfielders would touch the ball the most.

Here is, first, the average number of ball contacts by position and match. Touches on the ball can be anything here - passes, flick-ons, headers, shots on goal, you name it.

These numbers suggest that the average defender touched the ball significantly more than the average forward, with midfielders somewhere in the, well, middle. But what's perhaps most noticeable is that the average 55 ball contacts defenders make tower over the average 30 touches forwards get. Thus, according to these calculations, midfielders and defenders touch the back many more times than the guys tasked with putting the ball in the other side's net.

Could that be right? Has the pyramid really been completely inverted, with defenders dominating today's game?

Thursday, November 8, 2012

Back To Basics: Does the Premier League Make You Fat?

Does the Premier League make British men fat, or does male obesity help grow Premier League revenues? The data suggest it could go either way. Statistics from the NHS Information Centre's "Health Survey For England" and Deloitte's reports on clubs' financial statistics for the 1993-2010 period show that more revenue for the league has gone hand in hand with a greater proportion of males who are obese. Conversely, fewer obese men is associated with less revenue for football clubs.

When we combine the trends of financial good health and population bad health, a startling picture emerges: more obesity, more Premier League revenues. Less revenues, less obesity.

The correlation over the 15+ years is a whopping .93. It doesn't get much better than that.

But what does this mean?

Tuesday, November 6, 2012

Back To Basics: Normal Football and Skewed Distributions

On October 31, 2002, Madagascan side AS Adema cruised to an easy win against archrivals SOE (Olympique) Antananarivo. When all was said and done at the Stade Olympique I’Emyrne that day, Adema had won 149-0. No, that’s not a typo. Adema managed one goal every 36 seconds of the match, except they also had close to zero percent possession of the ball. As the BBC reported,
“… it was not their outstanding skill that led to the outlandish scoreline. It was because Olympique deliberately scored one own goal after another in protest over a refereeing decision. Radio Madagascar reported that Olympique began banging the ball into their own net after their coach Ratsimandresy Ratsarazaka lost his temper with the referee. Fans told the station that after the row between coach and official at Adema’s home ground in the port of Toamasina, the visitors directed each kick-off directly towards their own goal. Adema’s players simply stood around looking bemused as their opponents self-destructed.”
Even though there were 22 players on the pitch that day, along with a ball and a referee, the Adema-Antananarivo match had little to do with football as we know it. By repeatedly and intentionally scoring as many own goals as they could manage, Antananarivo had transformed the game from a football match and a contest against the other side into a contest of their own skill against the clock (and giving the referee the one-fingered salute in the process). Without opponents, teams would score as much as 90 minutes would allow – as the Adema-Antananarivo match revealed, we can assume that to be about 150 times per match, give or take, at a relatively even clip (quite a feat, actually, given the time it takes to fish the ball out of the net and return it to the center spot for a kick off).

The fact that the football played in the Madagascan match was barely recognizable as such makes it interesting for football analytics. It tells us things about football and football numbers that are worth keeping in mind as we dig more deeply (or before we dig deeply) into more complex data.