Many discussions are being held upon the "foreign player" regulations lately. FIFA ruled 6+5 regulation to be applied starting soon but EU dismissed the feasibility of this regulation already.
The point of discussion is always on some other view, depending on the nations and even within nations too. Those who think freedom in the number of foreign players will affect the national team performances as well as chances for promising youngsters are against those who support the freedom. People defending the freedom of number are suggesting that with correct transfer policies players outside their country may cost less and as long as they bear some talent they will provide a learning experience to those teenagers they block from regular first team opportunities.
The rule which was caused by a court order, known as the Bosman rule changed all the panorama of the issue. Bosman, who was looking for freedom to move away from a team when the contract expires led to free-roaming of EU-national players, also known as the Kolpak rule (which is not as well known as Bosman rule). Therefore, only non-EU players can be limited within EU member countries' leagues.
Every nation/league has their own regulations right now. In England the thing is totally different since their premier league is commercial. As long as you are not EU-national you need to receive a work permit from their committee. As long as you can be granted a work permit, there is no further limitation. The main purpose and focus of the work permit granting is based upon the "well being of the competition and national football". So a player is granted if he is considered to be useful to the league as a whole. The most commonly known quantitative aspect is that the player to be called to their national team on 75% of the games a national team plays in a certain recent period. But this is not the only regulation because they do not want to miss promising wonder kids too, so they may have special permits too.
In the latest European champions Spain, you are allowed to register 3 non-EU players. But as you may all know, Spanish La Liga is a paradise for many Latin American players. This is caused by the second nationality of some players. This is another advantage you can see in Serie A too. Many Argentinian players are tied to Spain or Italy when enough digging of ancestors are carried out. And when they prove that they have roots in Spain or Italy Argentinian players apply for second citizenship and are granted one most of the time. Same thing happens in Uruguayan players too. As for Portugal things get more interesting since they consider "any person who is a citizen of a nation whose native language is Portuguese is not considered as foreigners.". This makes even Angolan players eligible to play as non-foreign in BWin Liga. Also since Brazil's native language is Portuguese too, Portugal is the jumping board for Brazilian footballers to European football. They come to Portugal, play enough to be granted a Portuguese passport and then they are considered as EU-national. Netherlands, Germany, Russia and Greece had no limitations as of 2008. Many European clubs are lately picking up some smaller clubs as pilots (or feeders) and send their young talent foreigners to those clubs, for them to obtain EU-passport sooner. Belgium and Poland grant citizenship in 3 years for example.
Here in Turkey to apply for citizenship a player needs to stay in Turkey for a complete 5 years and he needs to be eligible for the national team, which means he shouldn't have played in his original nation's national team. If he provides these, then he is granted a Turkish citizenship and can play as a local player. The most common example to this is Mehmet Aurelio who now plays for Real Betis. If a player has played for their nation then they are expected to wait for another 5 years to be eligible as a local, which is almost impossible because this requires a player to play for Turkish clubs 10 years in a row. This does not occur often.
Those who defend against this freedom has found support from the top of World football, President Sepp Blatter, who thinks the freedom harms national football all around and teams are losing their identity. Such ideas find support also by national team director of the FAs who think such freedom prevents national talents to shine.
The European Championship winners are, Russia, Spain, Italy, Germany, Czechoslovakia, Germany, France, Netherlands, Denmark, Germany, France, Greece and Spain in chronological order, starting from 1960 to 2008. When you consider the latest competitions where foreign player freedom is increased you need to focus on the domestic leagues of those nations. Germany has full freedom, France has some limitations like Spain and Greece is also totally free. So it really does not seem to have a one-on-one effect upon national success. European football, going more and more global than any continent is becoming a single market. This widening provides many opportunities to talented players to roam, learn, teach and develop. But many think of them as cork stoppers in front of national young talents.
Of course, clubs' careless transfer policies support conservative scope unintentionally. Clubs buying not so talented players and playing them in front of their own kids, just because they are paying them more has some preventive aspect, honestly. But a bad example is not the example to show.
FIFA, however, already intervened and issued a limitation regulation, coming into effect step by step, which will be kick off at 2010-2011 and finalise at 2012-2013. 6+5 rule it is known as, means any team must have at least 6 players on the pitch who are eligible for the nations national team, +5 foreigners. 4+7, 5+6 and 6+5 is planned in the three year interval. This will affect some major clubs who are known with their player bias towards foreign players, such as Arsenal. But this proposed regulation has already been vetoed by the EU and European Parliament since it violates Article 39 as well as the Bosman ruling (and Kolpak ruling) mentioned above.
The issue is yet to be resolved since Blatter is insisting on the implementation of his 6+5 regulation, and doing his best to gather support. Whether he or the giant clubs of Europe will win is still yet to be seen.