Federer has won this clay court masters series title twice before, in 2006 and 2009 but this time he is probably more interested in the ranking points a win will give him, allowing him to surpass his arch-nemesis in the rankings for the first time since he lost the World #1 ranking to Rafael Nadal in June 2010.
Federer is playing excellent clay court tennis and so is Berdych. Federer has a 10-4 lead in their overall head-to-head but the tall Czech has won 3 of their last 5 meetings, including a very important victory in the 2010 Wimbledon quarterfinals. Berdych dismantled Fernando Verdasco 6-1 6-2 the day after the Spaniard became only the seventh person to defeat the King of (Red) Clay Rafael Nadal 6-3 3-6 7-5 on his favorite surface.
Federer is playing for history, and even if he doesn't overtake Nadal in this tournament, he will probably do so sometime this summer, probably around Wimbledon, and then continue on towards his primary goal, to reach #1 again.