Euro 2020 Interconnectivity Diagrams

 I'll begin with the unlabelled figure, because the labelled figure is very busy.  

The colours are my attempt at replicated the official UEFA Euro 2020 colours, as best I can with the limited Gephi colour palette.  

It is not the prettiest of this type of figure I've produced.  I particularly don't like the cluster right in the middle of the diagram (between Germany and Bayern Munich in the labelled figure).

I did warn you it was busy.  That busyness, the tightness of the clustering, was what really jumped out at me.  I've been making these diagrams since Euro 2012, and this is by far the most tightly inter-connected.

Looking back at the most recent international tournament before this (World Cup 2018), although that too was very busy, it wasn't as busy.  There was at least some space between most teams and some clearly outlying teams.

This time, the nearest there are to outlying teams are Finland, Russia, Ukraine and North Macedonia.  Wales and Turkey are not as outlying, but would be in the next layer in, followed by Portugal, Hungary and the Czech Republic.

Germany are the national team closest to the centre, while Atalanta are the club team closest to the centre.  Chelsea are represented by the most players, 15, followed by Manchester City and Bayern Munich on 14.

A couple of notes: no, you're not imagining it, Spain, Poland and the Netherlands have slightly smaller squads that the other teams.  Spain chose to only take 24 players, while Poland decided not to replace Arkadiusz Milik when he had to withdraw injured.  The Netherlands made the same choice when Donny van de Beek withdrew injured.

Every team except Wales have at least 1 player playing in the home league.  All the teams have at least one player playing in a foreign league.  That is a first, normally it's England who don't have any, but even they have 3 non-England-based players this time.  This may be the cause of the increased inter-connectedness of the diagram, although the number of non-English players in the Premier League has always been high.  Another cause could be the increase in squad size to 26 from 23 (so 72 extra players had everyone used the full 26 players).

Looking at the community view, there are 20 communities but 24 teams.  

France, Germany and Switzerland form one community, as do England and Spain, and Sweden and Denmark.  This again demonstrates how tightly interconnected parts of the diagrams are.

This is probably due to the number of club teams their national team players share.

Historically, teams that are outlying do less well.  With the way the tournament is organised, 8 teams are sent home after the first round.  From this diagram, I would expect Finland, Russia, Ukraine and North Macedonia to be amongst the 8, with some of the remaining 4 coming from Wales, Turkey, Hungary, Portugal and the Czech Republic (I didn't expect the last two).  

Two caveats, firstly, this prediction was made from the diagram only, and has ignored what has gone in the first two days of matches.  Secondly, it doesn't take the groups into account, so I know no one from group E is included but more than 2 groups have 2 teams named.  I am reasonably confident in the prediction about Finland, Russia, Ukraine and North Macedonia, a lot less confident about the others.  The lack of separation, due to the tight clustering, makes it hard to spot outliers.