I've read several times lately that Rafa must field his strongest starting XI for various big games against e.g. Chelsea, Barca, ManU. But do we have such a thing, as THE strongest starting XI, or is it merely a temporary term describing the best possible team available for the next match, considering such things as fitness, form etc? Is the term 'the strongest starting XI' a term of the past, when we only had 15-16 playes available? Does our current rotation policy mean that we're going from THE strongest starting XI to the currently strongest starting XI?