Again , 4 - 2 - 3 - 1 is it 's main formation , I agree .
Dortmound have defended with 4 - 4 - 1 - 1 several times this year .
4 - 2 - 3 - 1 is it 's main formation , I agree .
Dortmound have defended with 4 - 4 - 1 - 1 several times this year .