Washington Nationals First-Place Eliminiation Scenario
Washington must win 27 more games (27 total) to avoid elimination from first place.
Here are the final standings in a scenario in which Washington finishes in first place with 27 wins:

Team             W	L	PCT	GB
Washington       27	135	0.167	0.00
Miami            27	135	0.167	0.00
Philadelphia     27	135	0.167	0.00
New York         26	136	0.160	1.00
Atlanta          25	137	0.154	2.00

Tie breakers
Washington wins the series with Miami 13 games to 0
Washington wins the series with Philadelphia 7 games to 6

To construct the scenario, we start with the current standings in the division:
Team             W	L	GL	PCT	GB
Atlanta          0	0	162	0.000	0.0
Miami            0	0	162	0.000	0.0
New York         0	0	162	0.000	0.0
Philadelphia     0	0	162	0.000	0.0
Washington       0	0	162	0.000	0.0

Next, we show how the remaining series of games plays out in the scenario:

Atlanta currently has 0 win(s) against Miami and 0 loss(es).
Atlanta wins 6 additional game(s) against Miami and loses 7.
Atlanta loses the series 6 games to 7.
Atlanta wins 0 additional game(s) against teams outside the division and loses 110.

Atlanta currently has 0 win(s) against New York and 0 loss(es).
Atlanta wins 0 additional game(s) against New York and loses 13.
Atlanta loses the series 0 games to 13.
Atlanta wins 0 additional game(s) against teams outside the division and loses 110.

Atlanta currently has 0 win(s) against Philadelphia and 0 loss(es).
Atlanta wins 6 additional game(s) against Philadelphia and loses 7.
Atlanta loses the series 6 games to 7.
Atlanta wins 0 additional game(s) against teams outside the division and loses 110.

Atlanta currently has 0 win(s) against Washington and 0 loss(es).
Atlanta wins 13 additional game(s) against Washington and loses 0.
Atlanta wins the series 13 games to 0.
Atlanta wins 0 additional game(s) against teams outside the division and loses 110.

Miami currently has 0 win(s) against New York and 0 loss(es).
Miami wins 6 additional game(s) against New York and loses 7.
Miami loses the series 6 games to 7.
Miami wins 1 additional game(s) against teams outside the division and loses 109.

Miami currently has 0 win(s) against Philadelphia and 0 loss(es).
Miami wins 13 additional game(s) against Philadelphia and loses 0.
Miami wins the series 13 games to 0.
Miami wins 1 additional game(s) against teams outside the division and loses 109.

Miami currently has 0 win(s) against Washington and 0 loss(es).
Miami wins 0 additional game(s) against Washington and loses 13.
Miami loses the series 0 games to 13.
Miami wins 1 additional game(s) against teams outside the division and loses 109.

New York currently has 0 win(s) against Philadelphia and 0 loss(es).
New York wins 0 additional game(s) against Philadelphia and loses 13.
New York loses the series 0 games to 13.
New York wins 0 additional game(s) against teams outside the division and loses 110.

New York currently has 0 win(s) against Washington and 0 loss(es).
New York wins 6 additional game(s) against Washington and loses 7.
New York loses the series 6 games to 7.
New York wins 0 additional game(s) against teams outside the division and loses 110.

Philadelphia currently has 0 win(s) against Washington and 0 loss(es).
Philadelphia wins 6 additional game(s) against Washington and loses 7.
Philadelphia loses the series 6 games to 7.
Philadelphia wins 1 additional game(s) against teams outside the division and loses 109.

# Washington Nationals' magic number
# Washington's magic number
# Nationals' magic number
# MLB Playoff Race