Prior to his long-term injury Ben Arfa seamlessly transferred his Lyon form to the EPL.

by Jorge Torres

Not Premier League proven, a phrase used by pundits, fans and insiders to suggest that a particular foreign player may not cut it in the British Premier League. Like all pieces of conventional wisdom I wanted to take it on and separate myth from truth.

Too long, didn’t read version:
Most players need some time to adapt, but they do more than ok if they get time on the field. “Not premier league proven” is overstated.

Long, tedious yet complete version:
I started out by looking at every single transfer for offensive players in the last five seasons that came to the British Premier League for the first time and looked at their output in Goals and Assists in accordance to the minutes they played and compared it to the last season they had before coming to England.

Why offensive players? Offensive players (centre-forwards, wingers and attacking midfielders) have the job of producing results in the last third of the pitch, fans know what they want out of them, a centre-forward that doesn’t score is a scourge (Torres) instead of your average defender or midfielder who are not expected to come up with goals. Stats like “key passes” or completed pass percentages in the last third are great but extremely hard to come across for non insiders, and are very much non existent for unpopular leagues. So in the absence of an OPTA account we’ll have to make do with goals, assists and minutes played.

Without further ado, the data for the last 5 seasons:

Season 2010/2011

Season 2009/2010

Season 2008/2009

Season 2007/2008

Season 2006/2007

Age = the age the player had that season
GpA = short for Goals plus Assists
Minutes = The minutes that player had that season on all competitions with his club, not including friendlies or international appearances
Minutes played p/GpA = The minutes they player had on the pitch divided by the “GpA” number. The number is the average amount of minutes that player took to score or get an assist.
GpA p/game = Their “Minutes played p/GpA” number used as a divisor by 90 (90/Minutes played p/GpA). This number is the average that player performed on any given match over 90 minutes, as an example a .5 “GpA p/game” means that player scored or assisted once every two games.
Performance % = The comparison of the players “GpA p/game” of his debut Premier League season compared to his last “foreign” season by a simple rule of three. For example a 68% means that player only managed to reproduce 68% of his offensive game to the Premier League. Any number over 100% means that player did even better that his last season and “overproduced” what was expected of him.

Bolded percentages are the team’s average. All stats taken from Red numbers are the season average.

Taking the whole five seasons’ average we get 123% for performance, which would suggest the average transfer overproduced by 23% on their debut season. However there was still much disparity, some transfers were intended as experienced players who were expected to bring in short term results, other were youth players who were in for the long haul. Some players had fantastic seasons which brought up the average up too much.

I decided then to separate the players into those who experienced good form and those who didn’t, using 1000 minutes as my magic number to decide. Why 1000 minutes? It’s a good simple round number that equals around 11 matches. I arbitrarily decided that was a good measure to decide if a player had been offered a decent amount of minutes and a real chance to crack into the team.

After that I rounded up and separated the players further by grouping them into a range of “performance percentages”. The range goes from 0% to 300+%.  I put the numbers into a graph.

Here are the numbers and graph for those players over 1000 minutes played:

Numbers and graph for under 1000 minutes played:

Conclusions and closing Remarks:
Players who get over 1000m perform by an average of 78% compared to their previous year. Take into account a transfer which includes a change in country, language, culture, weather, friends and a difference in tactics or pace and you can see where the under performance comes from. A number close to 80% would get a pass in any school and suggests players do a remarkable job in fitting in into their new surroundings. The phrase “Not premier league proven” is thus another piece of conventional rhetoric which is blown out of proportion and not very useful.

It is however a very different story for players who get less than 1000m. Most are youngsters, flops or squad players who from very early on are expected to under perform. Their performance average is a pitiful 9% compared to their last year. It would be interesting to know if the lack of playing time makes them perform poorly or the fact that they are under performing makes them get less minutes. The answer is most probably a cross between the two.

Bonus Round:
If you want to predict how your clubs new transfer will do in the coming season use these functions:
Over 1000m (players you believe will be starters):
F(x)=[90/(Minutes Played last season/GpA last season)]*.78

Under 1000m (youngsters or bench players):
F(x)=[90/(Minutes Played last season/GpA last season)]*.05

The number you get will be the predicted “GpA p/game” stat. Fun!

You can follow Jorge on Twitter!/jtorres2_1