Don't know what you mean with the first sentence. Work ethic alone doesn't make you a great player. But in this particular case, Delpo's work ethic helped him maximize his potential in a way that Nalbandian unfortunately couldn't despite his great talent.
And of course winning a Slam makes a player great. I don't know why people act as if guys like Gaudio or Johansson fluked their titles or something. No one gave them anything. They saw a chance to get the most coveted prize in tennis and they took it, which many more talented players couldn't do, so extra credit to them.
Slams are the pinnacle of achievement in tennis and that doesn't change arbitrarily just because people feel that certain players aren't worthy of the title/fluked the title. It's bizarre that players who win one Slam seem to get more flak around here than some players who never won one. Johansson, Gaudio, Gomez (and Delpo too) managed to do what Murray (and others) has been chasing after for years with no success, they were not offered their titles, maybe they deserve some respect... Well, at least it's clear that they left their mark; even if it's merely to deride/mock their achievements, people keep mentioning them all the time years after they're retired.
I'm not saying other tournaments are irrelevant, of course they aren't. But those 4 tournaments are the ones everyone dreams of winning, the ones who etch one's name in tennis history forever. Something tells me that Murray would not finish his career very happy if he won 20+ masters titles but still got no Slam.
Greater is a very subjective term, there's no objective consensual criteria to rank the greatness of tennis players. But to me and people who share this view, who I am sure there are many including on this board, I'll always rate players who managed to get a Slam over those who didn't. If all other achievements remained equal and Del Potro had 2 Slams and Murray 1, I'd rate Murray ahead of Del Potro - and I do rate for instance Roddick ahead of Kafelniknov. But when a player has never managed to get one Slam, I really can't. Maybe I'm wrong, but that's how I see it; those who manage to get the greatest prize deserve to be rated above those who never did it.
This post reminds me of flyboy before he turned into Filo V. You could shorten that post by 2 thirds and still say the same things.
You'll have to excuse me but I don't have the energy to respond to you as I see it as a waste of time. I am
surprised though that the first sentence in my previous post was hard to understand.