I noticed something that worries me... Ian Desmond has the second-lowest BB/K rate in the majors and one of the lowest overall BB% rates. That means his wOBA is never going to be particularly high unless he hits for significantly more power than he has this season (it, not coincidentally, is also one of the lowest in the majors). I think his relatively high average is a bit of a mirage. So it may be that the Nats want to keep him at SS because they don't think he is a good enough hitter to play second. While it's always possible that his eye will improve significantly from where it is now, 4.6 BB% is really, really low for any starter, even a shortstop.