With the sheer dominance Federer had between 2004 and 2008, quite a few players were prevented from winning big titles. If it were not for Federer, who do you think would have had a much better career? I would say Andy Roddick, whose H2H records against Federer were so one-sided in favor of Federer. He lost many GS finals against Federer, so without Federer's invincible existance, Roddick would definitely have won much more than one major title, which he had won before Federer came into bloom. What do you think? Another player I can think of is Marat Safin, who also ended his career underachieved because of the presense of Federer, though he had a couple of wins over the Swiss at major tournaments. What do you think?