Andy Murray vs Rafael Nadal (who is the better defensive player / has better defense overall)?

[Ganstaz003]

By overall, I mean by all accounts, which includes defensive abilities / feats shown across all surfaces, tournaments and against every type of opposition.

Who is the better defensive player / has better defense between the two when taking into consideration all those factors?

 

[aman92]

Nadal at his prime has the best defense in history. This shouldn't even be a debate