Him feeling comfortable at a position has nothing to do with him being a 'natural' SS. Your definition of this term is just completely different from mine and anyone else's I've ever heard. Being a natural shortstop means you have the natural tools (arm, range, glove, etc.) to field SS well. If I feel comfortable playing SS in the major leagues, but I'm really, really bad, does that make me a 'natural' SS? Theriot is a passable SS, at best, and I'm glad Piniella is using him there because he's better than the alternative. Hopefully, Ronny can solidify that position by hitting as well as Riot while fielding it a little better. Again, I'm not too concerned about Riot's defense, because I don't really care that much about defense as long as the guy can make the routine plays, but to say that Riot is a 'natural' SS is more than a reach, IMO.