mike danny
Bionic Poster
Federer era: 2004-early 2010Nadal's overall "era" is 2008-2013. His best years coincided with some of the best years of Federer and Djokovic, but it doesn't mean he was usually the 2nd thoughest opponent during his era. Nadal was the overall thoughest opponent in 2008, early 2009, 2010 and 2013, so it's not like he usually was "the 2nd thoughest opponent" in 2008-2013. And specifically on clay, he has been the thoughest opponent from 2005 to 2019 (excluding 2015). Nadal's clay era (2005-2019) is certainly impressive, no one had a longer era of dominance on any surface.
Nadal era: 2008-2013
Djokovic era: 2011-2016 or early 2016.
I think that's about it.