Originally Posted by
technotronic
100 dinara is right... Here is a part of JustDoMes guide:
While there are many possible formations in Top 11, not all of them are valid. This is what it's commonly refered as "illegal formations". The exact rules and consequences aren't publicly known, but it's generally accepted that if your formation is illegal, you'll be penalised with a heavy loss of ball possession. And while it's possible to win with one of said formations, it's not a common occurance.
In order for a formation to be legal it must have:
-At least 3 defenders.
-At least 1 striker.
-At least a player in each flank.
-A goalkeeper.