To put this into perspective, how many times has each of them reached the semis of a slam dropping 0-1 sets?
Fed:
2019 RG
2018 AO
2017 Wim
2016 AO
2015 USO
2015 Wim
2014 Wim
2014 AO
2012 AO
2011 USO
2011 RG
2010 USO
2009 Wim
2008 Wim
2007 Wim
2007 RG
2007 AO
2006 USO
2006 Wim
2005 USO
2005 Wim
2005 RG
2005 AO
2004 Wim
2003 Wim
(25 total)
( 6 at AO, 4 at 10 at Wim, 5 at USO)
Fed won 11 out of these 25 = 44%
Overall : 15 SF at AO+8 SF at RG+13 SF at Wim+10 SF at USO = 46
So fed won 9 out 21 where he has lost 2 or more sets before the semi = 42.85%
So not that much of a difference in either
nadal:
2020 RG
2019 USO
2019 Wim
2019 RG
2019 AO
2018 RG
2017 RG
2014 RG
2014 AO
2013 USO
2012 RG
2012 AO
2011 USO
2010 USO
2010 RG
2009 AO
2008 Wim
2008 RG
2008 AO
2007 RG
2005 RG
(21 total)
(5 AO, 10 RG, 2 at Wim, 4 at USO)
Nadal won 15 of these 21 (71.43%)
Overall: 6 SF at AO, 13 at RG, 7 at Wim, 8 at USO = 34
So nadal won 5 of 13 where he lost 2 or more sets before the semi (38.46%)
Obviously clear difference for nadal when he loses more than a set
Djokovic:
2020 RG
2020 AO
2019 Wim
2019 RG
2018 Wim
2016 USO
2016 RG
2015 RG
2015 AO
2014 USO
2014 RG
2013 USO
2013 Wim
2013 RG
2012 USO
2012 Wim
2012 AO
2011 USO
2011 RG
2011 AO
2008 RG
2008 AO
(22 total)
( 5 at AO, 8 at RG, 4 at Wim, 5 at USO)
Djokovic won 9 out of these 22 (40.9%)
Overall: 6 SF at AO, 10 SF at RG, 9 SF at Wim, 11 SF at USO = 36
So Djokovic won 8 out of 14 where he lost 2 or more sets before the semi (57.14%)
Djokovic does clearly better when he loses more than a set before the semi