[Raynor]

A personal confrontation between Sauron and the new ringlord is what I have been talking about the whole time. In the battle between Sauron and the ringlord the armies would engage and play tremendous havoc with each other. In the confusion, Sauron would storm up to the pretender and personally settle matters with them.

I have never challenged the idea that Sauron would win in a direct single battle against anyone but Gandalf, although you keep returning to this; the meaning of my argument was that the ringlord would avoid, as I quoted from the letters, contemplating such a direct fight. I guess we will also have to agree to disagree that Sauron would be involved in a direct battle, out of several reasons: it seems to be the way things are in Arda that the greatest of leaders are not involved in direct battle (as Tolkien says in Myths Transformed: "the Government is always in Whitehall"); Melkor feared for his body, I think we can safely assume Sauron did too; IIRC, there was a single time when Sauron is mentioned to have engaged in direct combat, and he lost - I believe he learned the lesson; at the last battle, in front of the gates of Mordor, it is implied in LotR that Sauron believed the ringlord was present, but he did not come himself to fight.

There is another element that might be interesting to this discussion:

Originally Posted by Letter #131

Unless some other seized it and became possessed of it. If that happened, the new possessor could (if sufficiently strong and heroic by nature) challenge Sauron, become master of all that he had learned or done since the making of the One Ring, and so overthrow him and usurp his place.

I think it all comes down to the interpretation of what "challenge" mean. If it means direct confrontation, then it is probably down only to Gandalf; however, I think that challenge can be taken in a more general meaning; if that is the case, it appears that simple possession of the ring can provide, in itself, that which is required to overthrow Sauron.