Re: Bigger gap on clay- Serena vs Henin or Federer vs Nadal
I would pick Justine to win over Serena 100%. Given that Serena's mega weapon her serve is neutralized, Justine has more weapons to hurt Serena in a rally on clay. She has variety and much better defensive skills
The bigger problem Roger has when facing Nadal (apart from his backhand) is his inconsistency, he starts pretty well but then commits many unforced errors.
A peak Roger, though, would have minimum unforced errors and given that he is a much better offensive player the game would be close, as their first RG or Rome encounters were. Remember Roger even had matchpoints against Nadal in Rome on red clay so he could take a match against Nadal in RG if he played flawless tennis