Originally Posted by BobbyOne
All lists about playing strength are "feeled" lists, not arguments.
BobbyOne, I'm not sure what you mean by this. Level of play can be measured in any number of ways.
Match analysis is becoming increasingly sophisticated, and as I mentioned in some other thread there is a wealth of data for modern players.
The argument you made about Federer's peak level of play being lower than Nadal's and Djokovic's was controversial because so much is known about how these players perform and how their level of play measures statistically.
And match analysis is not the only way to judge playing strength. I can think of a handful of other methods, and you have used them yourself.
You can argue by analogy with other players, for example. To argue for Nusslein's superiority over von Cramm, you have connected them through Tilden: the argument is that Tilden defeated von Cramm in 1934, while Nusslein had an edge over Tilden in that year and in subsequent years.
That's similar to the way I connected Federer on the one hand, and Nadal and Djokovic on the other, through Roddick and Hewitt. I noted that Federer defeated peak Roddick and Hewitt more easily than Nadal and Djokovic were able to do in later years.
Then there are a player's yearly win/loss records, which all of us frequently use as a guide to judging when a player reaches his peak and when he starts to decline.
I don't know if you and PC1 saw the questions I put to you both in the other thread, about those last two methods -- but anyway my point here is that ranking players according to playing strength is not an exercise that is merely restricted to feeling. Perhaps I've misunderstood what you meant by feeled lists.