Houston Astros First-Place Eliminiation Scenario
Houston must win 0 more games (88 total) to avoid elimination from first place.
Here are the final standings in a scenario in which Houston finishes in first place with 88 wins:

Team             W	L	PCT	GB
Houston          88	74	0.543	0.00
Seattle          85	77	0.525	3.00
Texas            78	84	0.481	10.00
Oakland          69	93	0.426	19.00
Los Angeles      63	99	0.389	25.00

To construct the scenario, we start with the current standings in the division:
Team             W	L	GL	PCT	GB
Houston          88	73	1	0.547	0.0
Seattle          85	77	0	0.525	3.5
Texas            78	84	0	0.481	10.5
Oakland          69	93	0	0.426	19.5
Los Angeles      63	99	0	0.389	25.5

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

Houston currently has 9 win(s) against Los Angeles and 4 loss(es).
Houston and Los Angeles have no remaining games.
Houston wins the series 9 games to 4.
Houston wins 0 additional game(s) against teams outside the division and loses 1.

Houston currently has 8 win(s) against Oakland and 5 loss(es).
Houston and Oakland have no remaining games.
Houston wins the series 8 games to 5.
Houston wins 0 additional game(s) against teams outside the division and loses 1.

Houston currently has 5 win(s) against Seattle and 8 loss(es).
Houston and Seattle have no remaining games.
Houston loses the series 5 games to 8.
Houston wins 0 additional game(s) against teams outside the division and loses 1.

Houston currently has 7 win(s) against Texas and 6 loss(es).
Houston and Texas have no remaining games.
Houston wins the series 7 games to 6.
Houston wins 0 additional game(s) against teams outside the division and loses 1.

Los Angeles currently has 5 win(s) against Oakland and 8 loss(es).
Los Angeles and Oakland have no remaining games.
Los Angeles loses the series 5 games to 8.
Los Angeles wins 0 additional game(s) against teams outside the division and loses 0.

Los Angeles currently has 8 win(s) against Seattle and 5 loss(es).
Los Angeles and Seattle have no remaining games.
Los Angeles wins the series 8 games to 5.
Los Angeles wins 0 additional game(s) against teams outside the division and loses 0.

Los Angeles currently has 4 win(s) against Texas and 9 loss(es).
Los Angeles and Texas have no remaining games.
Los Angeles loses the series 4 games to 9.
Los Angeles wins 0 additional game(s) against teams outside the division and loses 0.

Oakland currently has 4 win(s) against Seattle and 9 loss(es).
Oakland and Seattle have no remaining games.
Oakland loses the series 4 games to 9.
Oakland wins 0 additional game(s) against teams outside the division and loses 0.

Oakland currently has 6 win(s) against Texas and 7 loss(es).
Oakland and Texas have no remaining games.
Oakland loses the series 6 games to 7.
Oakland wins 0 additional game(s) against teams outside the division and loses 0.

Seattle currently has 10 win(s) against Texas and 3 loss(es).
Seattle and Texas have no remaining games.
Seattle wins the series 10 games to 3.
Seattle wins 0 additional game(s) against teams outside the division and loses 0.

# Houston Astros' magic number
# Houston's magic number
# Astros' magic number
# MLB Playoff Race