Monday, June 20, 2011

Goalkeeping Stats across Europe - an analysis

101 goalkeepers made over ten starts in Europe's four major leagues during season 2010-12. Another fifty-six made at least one start in either the English Premiership, La Liga, the Bundesliga or Serie A. So after thirty eight games (thirty-four in Germany), which goalkeeper is best?Link

Of course evaluating custodians purely by stats is a fraught and inaccurate business. Goalkeepers, by their demeanour and wits bring more to a team than simply stopping shots, as per NHL netminders. They also command and organise their defence as well as arrange their players in best positions to defend set pieces. Also, they are often not at fault for the goals conceded, being beaten by lackadaisical or poor defending.

That's not to say that quantification of a goalkeeper's performance is useless. For one thing, we can evaluate definitively the differences across leagues.


LEAGUE

Total Starts

Conceded

Saves

Saves/Start

Save %

GAA

Serie A

760

953

2560

3.36

0.729

1.25

La Liga

760

1042

2645

3.48

0.717

1.37

EPL

760

1057

2403

3.17

0.695

1.39

Bundesliga

612

890

1925

3.13

0.684

1.45

GAA = Goals Allowed Average. Note the term "Start" has been used rather than "Games". Due to the data available, we weren't able to evaluate when goalkeepers conceded after coming on as a substitute. This also means that all the goals scored in a league throughout the course of the season may not be included in this table.

Perhaps as a result of a slower game tempo, of a reliance on a star individual, miserly defence or even plain and simple goalkeeping ability, Serie A produced consistently the best goalkeeper metrics across the board. That is, Goalkeepers in Italy conceded less goals per game, had a higher save percentage and produced a high level of saves per start.

Italian football is notorious for it's slower pace - unless you're Napoli or Udinese this season - and infamous for low goalscoring. That isn't necessarily borne out here - while the GAA was lower than in the other three major leagues, the increased Save Percentage counteracts that. This could also be a tactical measure, where Italian defenders are more "pigeon-holed" as defensive stoppers, eschewing forward play in favour of stolid defence.

Most surprising was the relative decrease in saves across the water in England. The Premiership produced the second-lowest save percentage and the second-highest GAA. Again, tactical considerations could be keeping these averages low or simply that the offensive play is superior. This could both back up and dispel the popular preconception that the Premier League is the most exciting and balanced in Europe, so while it's interesting data it's hardly definitive. While this table takes into account goalkeeper performance, it is we have said, impossible to divorce that totally from a defence's (in)ability.

How would these numbers look then, if we removed the backups? Most clubs have one primary goalkeeper and at least one creditable custodian in reserve - take for example Italian Champions AC Milan who fielded Christian Abbiati thirty-five times during 2010-11 and Marco Amelia during the remaining three matches. The following table has removed all the players with less than ten league starts. The numbers don't change much at all:


LEAGUE

Total Starts

Conceded

Saves

Saves/Start

Save %

GAA

Serie A

732

912

2469

3.37

0.730

1.25

La Liga

698

938

2432

3.48

0.722

1.34

EPL

714

988

2283

3.20

0.698

1.38

Bundesliga

553

795

1758

3.18

0.689

1.44

The greatest difference between the two is a minor increase in German Saves per Start and Save Percentage, while Spanish Save Percentage increased mildly as well. The GAAs, though changed in all leagues except Serie A, were minor adjustments. While it was a nice thought that a league's overall goalkeeping quality could indicate how crucial defences were to the numbers, it is unproveable with the above results.

It's perhaps telling that the greatest difference in the table above comes from Germany & La Liga's goalkeeping starts: during the course of the Spanish season, forty-three players got a start between the sticks. Thirty-eight Goalkeepers got starts in the Bundesliga (forty-two, if adjusted for a twenty-team league), thirty-nine Italian league players and thirty-seven in the EPL. While the vast majority of each team's matches were played by the starting GK (over 90% in all leagues), Germany had the most trust in their backups.

This means that backup keepers, whether for reasons of injury, form or rotation claimed 9.93% of the available starts in Germany while in Italy, starters accounted for an enormous 96.3% of the available starts.

In part two, we'll go through Europe's best and brightest goalkeepers by save percentage, Goals Allowed average and by league. In the meantime, you can find all the raw data here at Balanced Sports' Goalkeeper Stats page.

2 comments:

  1. Hi there. May I ask, from where did you get the stats for the leagues except for the Premiership?

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  2. Emre - I got the raw data from ESPN Soccernet's team pages. They keep data differently to each of the major leagues and because there was a source of data which (hopefully) kept stats across Europe equally, I opted to use that rather than data from individual teams.

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