Their defensive approach is spot on really; their left sided midfielder moves in to become an extra central midfielder, leaving Arbeloa free, while their right sided midfielder (Pereyra i think) stays wide, keeping tabs on Marcelo. This means that the only player Real Madrid can consistenly find open in the final third is Arbeloa, whom, with all due respect, is not as good on the ball as Marcelo, Alonso or Ozil, who are the players being marked instead.