How can what people hypothesize be used to determine who is the greater player over tangible results. It is a contradiction of the highest order to suggest winning any match can result in diminishing of your greatness.
Additionally, why do you rate an individual match-up with greater regard than vs the entire field? This sport is about performance against all peers and always has been. When pro-tours were played back in the day where more than 2 people competed, the tour winner was the person with the best winning percentage, not the one who held the head-to-head among the top 2.
There was tour when Pancho Gonzales lost the head to head to Lew Hoad 13-15, but beat Anderson and Cooper 34-0, while Hoad beat them 27-7. Gonzales was named the tour champion. Was Hoad greater?
Its the same thing with Djokovic vs Nadal. The other matches matter and saying that a loss to nadal + a win over someone else is worse than simply just losing to someone else with no win doesn't make much sense.
You're being unnecessarily reductive, and taking a far too quantitative approach to a dynamic issue. Novak beating Stan and then losing to Nadal last year increased the absolute value of his career at the Open, to the extent a final appearance is more impressive than a semifinal appearance. Novak losing the rubber match between he and Nadal, and in so doing falling behind him in the high stakes encounters and number of titles at the tournament hurt his comparative value to Nadal.
Moreover, I believe that title bouts are utterly unique, and deserve special consideration - hence my inclusion of winning percentage in finals interacting with total finals reached. Novak has been labelled as somebody who can't deliver when the lights are brightest - he just recently spoke about how much that issue was in his head through last Sunday, and how important it was for him to beat Roger. So beating Stan and losing to Rafa actually reinforced a negative stereotype about his game, psyche, and championship demeanor - that he's not clutch - and therefore did harm to his legacy at the Open, regardless of how many quantitative metrics he performed well in.
I can't tell you how derisively LeBron James was treated by fans and the media when he couldn't win in the conference and NBA finals through 2012. How about Peyton Manning or Wayne Rooney? Not a playoff performer - not clutch, etc. Ever read any articles comparing Peyton to his little brother Eli? The former blew the latter out of the water stats-wise, but Eli had mystique because he won the Super Bowl 2x via clutch play. Maybe that's not fair, but it's relevant. And it's even less fair for top guys in team sports, because they have to rely on others much moreso than tennis players, who have their own fates in their own hands.
Again, you gotta look deeper than the numbers - I don't mean to be facile, but these are people, not machines. Some guys handle the pressure of the championship match (and the final weekend) better than others, which isn't adequately captured by numbers alone, but is incredibly relevant to comparing careers at one major or another.
Usually these things average out, particularly when players are within 1-2 years of each other age-wise. I'm sure we'll have a pretty clear picture of who had the "greater" career b/w the two in NYC when all is said and done. But the idea that actual matches at the actual venue b/w the two players lack standalone value - well, that I just can't get behind.
Context matters, however messy it may be. You may find Novak losing a few more championship matches in a row in New York to be great for his career, since it seems to lend itself to a rockin' winning percentage and lots of ranking points. I think it's a problem for him - that if it played out that way, he'd be just another of those guys who too often choke in the clutch, despite having all the talent in the world.
Just so I'm clear, since we've drilled down pretty deep here - we agree that titles trump all, and the only question is how much to value performances against the field versus performances against the player as tiebreakers when both players have the same number of titles - is that right?