Thursday, July 03, 2014

Harald's Original Miscellany - More Truth about Football - Part 3

To change the team means to earn more
money...what about the football millionaires?
How often do they change the team?
Are you ready for more statistics on your favorite kind of sports? Well, data is fun, and obviously Big Data means Big Fun. There are lot's of interesting things to discover while exploring data, and wikipedia (i.e. dbpedia for the insiders) provides all the necessary means.

Have you ever wondered about this kind of slave trade in professional football? Well, I wouldn't exactly call the transfer of a millionaire to a higher paying job a 'slave trade'. But, have you ever thought about the following question: Do the real good (and well paid) players more often change the team - or is it vice versa, that teams try to get rid of players that have a bad season or are on the decline? Who knows? Let's have a look on the data:
TeamChanges NumPlayers
16 2
15 26
14 84
13 287
12 792
11 2247
10 3848
9 5109
8 6464
7 8110
6 9790
5 11264
4 11837
3 11448
2 10961
1 6515
Here, we have a table providing an overview about how many players (in wikipedia) have changed their team for how many times [1]. Obviously, it seems to be some kind of Gaussian distribution with a peak between 2 and 6 team switches. OK, what about the players? Where are the top players listed in this table? Well, David Beckham switched team 11 times according to wikipedia, Cristiano Ronaldo 8 times, Thierry Henry 9 times. At least these numbers are above average which we had identified to be between 2 and 6. This seems to give proof to our original assumption.

person TeamChanges popularity
http://dbpedia.org/resource/Cristiano_Ronaldo 8 1794
http://dbpedia.org/resource/David_Beckham 11 1572
http://dbpedia.org/resource/Thierry_Henry 9 1414
http://dbpedia.org/resource/Lionel_Messi 7 1404
http://dbpedia.org/resource/Wayne_Rooney 5 1343
http://dbpedia.org/resource/Frank_Lampard 5 1188
http://dbpedia.org/resource/Pel%C3%A9 4 1111
http://dbpedia.org/resource/Didier_Drogba 8 1047
http://dbpedia.org/resource/Ronaldo 10 1037
http://dbpedia.org/resource/Michael_Owen 6 1011

But, we get a better overview, if we look at the average popularity of each switching group in the table [3]:
TeamChanges NumPlayers avgindegree
16 2 107.5
15 26 76.769230769230769
14 84 47.297619047619048
13 287 60.885017421602787
12 788 45.073604060913706
11 2235 37.206263982102908
10 3800 32.577631578947368
9 5023 30.939080230937687
8 6332 29.685881238155401
7 7935 25.499054820415879
6 9525 23.188346456692913
5 10886 18.682895462061363
4 11423 14.937844699290904
3 10842 11.131802250507286
2 10089 7.704628803647537
1 5534 5.19588001445609
As we had originally thought, on the average, the popularity of the players rises with the number of team changes. Although the top group with 16 changes is far from the highest possible popularity scores (as e.g. 1572 for David Beckham). Hmm, maybe there is a correlation among the number of achieved goals with the number of team changes? Is it more likely that a top goal hunter switches team more often? Let's have a look [4]:
TeamChanges NumPlayers AvgGoals
16 2 22.5
15 26 28.807692307692308
14 83 37.855421686746988
13 287 38.062717770034843
12 781 39.939820742637644
11 2205 38.625850340136054
10 3784 35.646141649048626
9 4980 32.826907630522088
8 6296 29.489517153748412
7 7826 24.455788397648863
6 9314 21.937835516426884
5 10471 18.655142775284118
4 10627 16.317869577491296
3 9612 12.756450270495214
2 7193 9.911858751564021
1 4624 4.444204152249135

Looks interesting. Top goal scorer have 9 to 14 team switches. This is way above the average. Thus, the more goals you score, the more often you will have the chance of being transferred (and thus earn more money). Players that don't score goals will obviously not be transferred (that often).

References: