The Bosman ruling - the law that allows players in the EU switch clubs at the end of their contract without a transfer fee - was only introduced in 1995. Jean-Marc Bosman won a European Court of Justice decision to allow him to move on a free transfer from RFC Liege in Belgium to Dunkerque in France. The ruling has seen the likes of Sol Campbell, Andrea Pirlo and Robert Lewandowski all make high-profile moves to rival clubs for no fee.