I did up some clinching scenarios, hope they are right. Sunday is really the first realistic chance to clinch. Monday or Tuesday night would be most likely:
To clinch on the following day:
Friday:
impossible
Saturday:
Nats win first 2 against Braves
and
Dodger's lose first 3 games to Cards
and
Pittsburg loses first 2 against the cubs
and
Brewers and Phillies each lose a game.
Sunday:
Nats sweep the Braves and Pittsburg loses one game.
or
Nats go 2-1 against the Braves
and
Dodgers lose at least 3 games or Dodgers win all 4
and
Pittsburg loses 2 more games
and
Brewers and Phillies each lose 1 more game.
Monday:
Nats win next 4 games
or Nats go 3-1 and Pittsburg loses one game
or Nats go 2-2
and Pittsburg loses 2 more games
and Brewers and Phillies each lose 1 more
and Dodgers lose at least 3 or Cards lose at least 4.
or Nats go 1-3
and Pittsburg loses 3 more games
and Brewers and Phillies each lose 2 more
and Dodgers lose at least 4 or Cards lose at least 5.
Tuesday:
Nats go 4-1
or Nats go 3-2 and Pittsburg loses one game
or Nats go 2-3
and Pittsburg loses 2 more games
and Brewers and Phillies each lose 1 more
and Dodgers lose at least 3 or Cards lose at least 4.
or Nats go 1-4
and Pittsburg loses 3 more games
and Brewers and Phillies each lose 2 more
and Dodgers lose at least 4 or Cards lose at least 5.