physicality of the game today means that no one will achieve the grand slam
non-calender year grand slam is a more realistic prospect
sampras was 2 matches away from it in 94, federer was 2 sets away in 06 and 07, nadal was 2 matches away in 10, djokovic was 2 sets away this year
it's not a coincidence that it's become easier with the homogenized surfaces and playing styles
career grand slam has also become a lot more achievable. it was a shock when agassi did it in 99
federer has had the honestly to admit that the changes (uniform) in surfaces has led to himself and nadal achieving it so fast
don't believe nadal has commented on it.
can't see either of them winning it in the 80s or 90s. nadal would come unstuck at the AO and the US, federer at the FO