War Safin!
Professional
Sampras was not on his game for a large % of 2001:Dude, you are going in circles.
Again, every reasonable poster on this boards thinks, that neither Sampras, nor Federer was at their best, when they met. They met and Federer won, displaying in the process some of the qualities, that made him famos later in his career. Sampras was on his game, so do not try do downgrade Federer's win, just like noone in his right mind is trying to downgrade a champion like Sampras, just because he lost to the future 7 times winner there.
As for Henman vs. Federer. I remember that Henman was on fire in that match (I take it, that, when he saw, that Sampras went down, he probably thought that that is his chance for a title there and was extra motivated), displaying his splendid grasscourt game and lobbing Federer to death. And let us not forget, that Federer lost two tie-breaks in that match. In one of them he held two setpoints and the other was 5-2 or 5-3 (if memory serves) in his favour, before the importance of the occasion took its toll. The other set, that Henman won he broke Federer in the last possible moment. So, having in mind, that Henman was no slouch on grass, we can surely assume, that Federer displayed a fairly high level of tennis against him.
* Didnt win a title all year
* Only made one final in the first 6 months
* Lost early in the AusO
* Came into Wimbledon with a 25-10 season
* Taken to 5 sets by the World #256 in that same Wimbledon tournament
He only raised his game following Wimbledon, making 3 finals..oh yes, and losing all of them.
He was clearly on-the-slide and for the reat of his career really only showed up for the US Open in 2002.