Chris Kahrl of Baseball Prospectus writes in Transaction Analysis that Washington is now using a ten-man pitching staff:

Progress can take all sorts of shapes, although sometimes it needs a sing-along ball. Even so, happy notes are to be found in the immediate assurances given that Chavez is only here to be a reserve, pinch-running and handling defensive substitutions and such. And the idea that the Nats are willing to--gasp--go with ten pitchers or--gasp again--do without a situational lefty… well, it's the world turned upside down, you'd think. It's cool to see that Frank Robinson has the gumption, and Jim Bowden the flexibility, to run with this sort of roster, but I can't help but wonder if necessity, and not any peculiar genius, is the unwed mother that produced this invention, a leftover of the organization's long bender with Omar Minaya. When your choices are bringing back Joe Horgan or doing without a lefty, you might end up doing something bold because you don't have a whole lot of choice.

If Washington keeps winning, maybe other teams will notice.