IvanAndreevich
Legend
In my opinion, Del Potro has to win in 3 or 4 sets. Anything else and Federer will take it. H2H seems to clearly favor Federer so far: http://www.atpworldtour.com/3/en/players/headtohead/?player1=del+potro&player2=federer In fact, Del Potro has lost all 7 sets so far, never taking one to a tiebreak.