Right from pre-season, Ancelotti was praising Modric's performances in midfield, the same position he plays in for Croatia. Luka was the brain that Ancelotti was looking for for Real Madrid. Modric accepted the challenge comfortably, and the team began to operate in the style of his simple football with certain British touches in it, based on two concepts - a fast touch and offering the ball to a team-mate.

Modric's dynamism in midfield has meant that Real Madrid has more rhythm when on the ball, and can cover a lot more ground, even though Modric is not a player for grand physical displays.
Despite Ancelotti having tried out a number of systems, the common denominator has always been Modric as a reference point in midfield. And since Alonso came back, he has formed a solid partnership with Xabi.
Modric has played in 22 games so far this season, starting in 17, and especially in the Champions League where he started in all 5 matches he has played in.

http://www.marca.com/2013/12/26/en/football/real_madrid/1388079906.html