Photo Study of the Roger Federer Forehand

Here, Roger illustrates a fairly standard racquet position for the farthest-back point of the backswing. Having the racquet point at the back fence is entirely standard, but Roger's stringbed is facing downward more than one would usually see with the grip halfway between Eastern forehand and Semi-Western he is using. The racquet should face downward somewhat on the backswing, because it naturally opens up as you swing forward.

From the position of his hips, it appears that Roger is using roughly a 3/4-open stance, which will add considerable rotational energy to his swing.