I'm happy for Juan Martin Del Potro and glad he won it . He must've been really happy considering it was his first grand slam title . Still, after not losing a match at the U.S. Open in almost 6 years Federer was due for a bad day and it finally happened . He was off and not himself . One hopes to peak by the time they reach the finals , but indeed Roger finally had an off day , as evidenced by a far below average first serve percentage. Del Potro was also fortunate that he was playing a Nadal that has not found his normal groove yet since his rest from knee problems . A top form Federer or Nadal would have beaten Dep Potro , but take nothing away from him .
Del Potro has been a force to be reckoned in the not so distant past though , nearly defeating Federer at the French and the Swede's first victory there . He's lost a lot of close ones so it's good to see him finally win one of those . He's given top players all they could handle for awhile now and steadily improved and therefore I don't see this as a fluke for Del Potro at all . He just made the men's draws in any future major all the more interesting and I see him winning more grand slam events in the future 
Federer can't be too sad though , he's what , made it to the FINALS of the last SEVEN grand slam events in a row and won three of those finals . Not too shabby at all ! And here not all that long ago people were predicting Feder's soon to be demise , and then look what he did 
I agree with most of it. Except that part.
Roger Federer can play unbelievable tennis if everything is going according to plan. When there's some minor disturbance he isn't half as good. Despite the lousy servis he dominated the match the first two sets (luckily Del Potro won the second 7:6) but after Del Potro took his first serve game he started making a lot more mistakes, his game was less convicing... As if he was scared all of a sudden.
And I find pathetic that a player of his caliber, who has been through so much on the court, played hundreds of matches and numerous situations can get that worked up when someone offers him a challenge. It has happened many times, especially with Rafa Nadal.
When Rafa pushed his buttons and Fedex couldn't get every ball in the court, he lost the game. That's why they have a 13:7 record because Federer can only win if he's 100% sure he's the best. When you challenge him, he cracks. And that has happened multiple times, no matter how many grand slams he's got. He is the champion, a true chamion.. No one can deny that.
But he lacks what it takes to be the greatest of all time. And that is being psychologically strong enough to overcome and obsticle. In my opinion he's been afraid of Rafa since Rafa beat him when he was only 18 years old and Fedex was NR.1. I think something similar will happen with his future matches against Del Potro.
PS - remember Federer's last game against Tsonga where there was 1:1 in sets and Fedex lead 5:1 in the third set, serving for the win. Tsonga broke his serve and eventually won the match with 7:6 in the tie break.
He lost 5:1 lead after given a little nudge. That's weak in my opinion. That was few weeks ago.
