Transfer policy #3: how well do players adapt?

by Dr Adrian Worton

By analysing transfers made by Premier League clubs over the last four seasons, we have been able to come up with a measure of how good-value signings have been. This method was then used to see where the best-value players have been bought from. 

This time we will be considering the past form of signings in order to measure how well they have adapted to the Premier League.

The data

As before, we use all transfers made by Premier League clubs made between the 2013/14 and 2016/17 seasons, where the player has made at least ten appearances for his new club (explained here). As we are considering past performances as well, this time we will only consider players who played at least ten matches for their previous club before moving.

For each player, the average rating (according to WhoScored) from their last three seasons with their old club is compared to the average rating in their first three seasons with their new club. If a player was on loan just before moving, they are counted as moving from the loaned club, since that is where their ratings are for. 

The leagues for which ratings are recorded, and therefore can be used, are:

• ​England's Premier League (153 transfers)
• England's Championship (36 transfers)
• France's Ligue 1 (36 transfers)
• Germany's Bundesliga (33 transfers)
• Italy's Serie A (31 transfers)
• Netherland's Eredivisie (13 transfers)
• Russia's Premier League (5 transfers)
• Spain's La Liga (43 transfers)

The results

For each league, the average difference in ratings is recorded. The results of which can be seen below:

The first thing to note is that for all leagues, the difference is negative. This means that their performance has dropped after moving to the Premier League. This isn't a huge surprise, as we would expect a player who has been bought to have played well enough to merit a transfer, after which regression to the mean may occur (which is explained here). There is also the time required for a player to become familiar with his new club, or indeed for his manager to find the best way of utilising him. 

As we would expect, the English Premier League has the smallest difference in performance levels. It is also reasonable to expect La Liga to follow; this is widely considered to be the highest-quality league in the world, and therefore players who play well in that should find that they are of sufficient quality to play in the Premier League. 

It is interesting to see that players moving into the Premier League from the Championship play at closer to their previous level than those from Serie A and the Bundesliga, both highly-regarded leagues. In other words, a player playing at a high level in the Championship is more likely to keep up that form in the Premier League than someone from the top leagues in Italy and Germany. Particularly given the recent success of German sides, this is a surprising result.

Significantly behind the other leagues is the Eredivisie, where signings have performed significantly below their level in the Netherlands. This is partly driven by players who have particularly struggled in England since moving, such as Depay at Manchester United, Janssen at Tottenham Hotspur or Henriksen at Hull City. It is also driven by players who was performing at an extremely high level in the Netherlands, whose performances in England have been good, but less spectacular, such as Southampton's Pellé and Tadic or Newcastle United's Wijnaldum. 

Who were the best and worst adapters? 

We can also use this method to look at the transfers in our data set to find the best and worst players at adapting to the Premier League. Click the name of each division below to see the five best and worst adapters from each league. The Russian Premier League is left out, since there are only five transfers in total.

Premier League

​Best adapters

Player	Previous club	New club	Old rating	New rating	Difference
Moses, V	Liverpool	Stoke City	6.35	7.45	+1.10
Townsend, A	Tottenham Hotspur	Newcastle United	6.76	7.35	+0.59
Sigurdsson, G	Tottenham Hotspur	Swansea City	6.56	7.09	+0.53
Benteke, C	Liverpool	Crystal Palace	6.83	7.35	0.52
Bertrand, R	Aston Villa	Southampton	6.44	6.95	+0.51

​Worst adapters

Player	Previous club	New club	Old rating	New rating	Difference
Moses, V	Stoke City	West Ham United	7.45	6.52	-0.93
Ayew, A	Swansea City	West Ham United	6.98	6.24	-0.74
Sidwell, S	Fulham	Stoke City	7.04	6.30	-0.74
Lambert, R	Southampton	Liverpool	7.03	6.33	-0.70
Rémy, L	Newcastle United	Chelsea	7.15	6.45	-0.70

Championship

Best adapters

Player	Previous club	New club	Old rating	New rating	Difference
Afobe, B	Wolves	Bournemouth	6.42	7.10	+0.68
Grant, L	Derby County	Stoke City	6.72	6.99	+0.27
Phillips, M	QPR	West Bromwich Albion	6.99	7.13	+0.14
Boyd, G	Hull City	Burnley	6.75	6.85	+0.10
Fábio	Cardiff City	Middlesbrough	6.94	6.99	+0.05

Worst adapters

Player	Previous club	New club	Old rating	New rating	Difference
Sako, B	Wolves	Crystal Palace	7.31	6.54	-0.77
Gestede, R	Blackburn Rovers	Aston Villa	7.56	6.83	-0.73
Sandro	QPR	West Bromwich Albion	6.99	6.39	-0.60
Murray, G	Reading	Bournemouth	6.96	6.38	-0.58
Hennessey, W	Wolves	Crystal Palace	7.01	6.48	-0.53

Ligue 1

​Best adapters

Player	Previous club	New club	Old rating	New rating	Difference
Martial, A	Monaco	Manchester United	6.70	7.11	+0.41
Payet, D	Marseille	West Ham United	7.27	7.67	+0.40
Cabaye, Y	PSG	Crystal Palace	6.68	7.05	+0.37
Lovren, D	Lyon	Southampton	6.95	7.32	+0.37
Kanté, N	Caen	Leicester City	7.36	7.61	+0.25

​Worst adapters

Player	Previous club	New club	Old rating	New rating	Difference
Thauvin, F	Marseille	Newcastle United	6.94	6.20	-0.74
Manquillo, J	Marseille	Sunderland	7.06	6.41	-0.65
Batshuayi, M	Marseille	Chelsea	6.74	6.16	-0.58
Stambouli, B	Montpellier	Tottenham Hotspur	7.04	6.52	-0.52
Ibrahimovic, Z	PSG	Manchester United	7.95	7.44	-0.51

Bundesliga

Best adapters

Player	Previous club	New club	Old rating	New rating	Difference
Pocognoli, S	Hannover 96	West Bromwich Albion	6.62	6.91	+0.29
Fuchs, C	Schalke 04	Leicester City	7.04	7.29	+0.25
Romeu, O	VfB Stuttgart	Southampton	6.72	6.90	+0.18
Arnautovic, M	Werder Bremen	Stoke City	6.80	6.95	+0.15
Kirchhoff, J	Schalke 04	Sunderland	6.78	6.88	+0.10

Worst adapters

Player	Previous club	New club	Old rating	New rating	Difference
Schürrle, A	Bayer Leverkusen	Chelsea	7.53	6.79	-0.74
Mkhitaryan, H	Borussia Dortmund	Manchester United	7.62	6.93	-0.69
Schweinsteiger, B	Bayern Munich	Manchester United	7.47	6.78	-0.69
Joselu	Hannover 96	Stoke City	7.21	6.59	-0.62
Rahman, A	FC Augsberg	Chelsea	7.37	6.75	-0.62

Serie A

Best adapters

Player	Previous club	New club	Old rating	New rating	Difference
Alonso, M	Fiorentina	Chelsea	7.12	7.51	+0.39
Isla, M	Juventus	QPR	6.67	6.98	+0.31
Kozák, L	Lazio	Aston Villa	6.44	6.61	+0.17
Shaqiri, X	Inter Milan	Stoke City	6.69	6.85	+0.16
Pogba, P	Juventus	Manchester United	7.71	7.72	+0.01

Worst adapters

Player	Previous club	New club	Old rating	New rating	Difference
Cuadrado, J	Fiorentina	Chelsea	7.61	6.37	-1.24
Balotelli, M	AC Milan	Liverpool	7.59	6.54	-1.05
Álvarez, R	Inter Milan	Sunderland	7.15	6.48	-0.67
Jovetic, S	Fiorentina	Manchester City	7.37	6.82	-0.55
Suárez, M	Fiorentina	Watford	6.91	6.38	-0.53

eredivisie

Best adapters

Player	Previous club	New club	Old rating	New rating	Difference
Martina, C	FC Twente	Southampton	6.75	6.72	-0.03
van Aanholt, P	Vitesse	Sunderland	7.12	7.06	-0.06
Blind, D	Ajax	Manchester United	7.33	7.19	-0.14
Janmaat, D	Feyenoord	Newcastle United	7.22	6.88	-0.34
Wijnaldum, G	PSV Eindhoven	Newcastle United	7.37	6.91	-0.46

Worst adapters

Player	Previous club	New club	Old rating	New rating	Difference
Depay, M	PSV Eindhoven	Manchester United	7.83	6.33	-1.50
Janssen, V	AZ Alkmaar	Tottenham Hotspur	7.52	6.23	-1.29
Pellé, G	Feyenoord	Southampton	7.97	7.05	-0.92
Henriksen, M	AZ Alkmaar	Hull City	7.14	6.22	-0.92
Tadic, D	FC Twente	Southampton	7.80	6.95	-0.85

La Liga

Best adapters

Player	Previous club	New club	Old rating	New rating	Difference
Sánchez, A	Barcelona	Arsenal	7.34	7.80	+0.46
Llorente, F	Sevilla	Swansea City	6.59	6.92	+0.33
Alderweireld, T	Atlético Madrid	Southampton	6.87	7.07	+0.20
Barragán, A	Valencia	Middlesbrough	6.83	7.02	+0.19
Costa, D	Atlético Madrid	Chelsea	7.20	7.37	+0.17

Worst adapters

Player	Previous club	New club	Old rating	New rating	Difference
Aspas, I	Celta Vigo	Liverpool	7.14	6.21	-0.93
Soldado, R	Valencia	Tottenham Hotspur	7.10	6.39	-0.71
Bastón	Eibar	Swansea City	6.78	6.11	-0.67
Nolito	Celta Vigo	Manchester City	7.34	6.77	-0.57
Bravo, C	Barcelona	Manchester City	6.87	6.35	-0.52

The most remarkable thing to note is that Victor Moses appears to be the best and worst adapters at a new club for players signed from Premier League rivals, thanks to a freakishly good season on loan with Stoke City. Other notable players are Memphis Depay, whose difference is the largest of any player in the data set, signifying how poorly he adapted to his move to Old Trafford.

Summary

After studying the effects of the price tag on a player's performance, now we can consider his previous performance as well to identify which signings have performed above and below expectations. Next time we will be bringing this altogether in order to rate each club's recent transfer activity.