Please. What Debt. Roger would have won 20 Slams by now if it wasn't for Rafa. He'd have at least 2 french Opens and 6 Wimbeldons. Roger is miserable just like he made Roddick miserable. Do you think Roddick is thankful to Roger?
My thoughts exactly. I don't buy this concept that's being thrown around nowadays saying Nadal improves Federer's legacy. Before 2008 Federer was swatting opposition like flies and looked like he was leagues ahead of anyone and everyone else.
Once Djokovic and Nadal beat him in the first 3 GS's of 2008 the suggestion came that Federer was dominating during a mug era and didn't have any real opposition.
It didn't help that Roddick, Hewitt, Baghdatis, Gonzalez and other previous Grand Slam finalists no longer looked like credible opponents.
The last time Safin won a tournament was January 2005 (Australian Open) and has only made 2 finals since, both in the Kremlin Cup.
Gonzalez has never won an ATP Masters Series or a Grand Slam, and has only 3 titles outside of clay.
Hewitt has only won 3 ATP tournaments since 2005, and hasn't won a Masters Series or a GS since 2003.
Baghdatis has only won 2 ATP titles in his career.
Now you compare this to Djokovic, who has won 4 masters series, a masters cup and a Grand Slam in the last 2 years, and Nadal who has 5 Masters Series (11 in total) and 4 Grand Slams (6 in total) in the last 2 years.
Conclusion: Nadal doesn't make Federer look better, he only makes the previous era look really weak. It would be more accurate to say that Nadal owes a debt to Federer who makes his 6 Grand Slams look even more special.