Houston Astros First-Place Eliminiation Scenario
Houston must win 27 more games (39 total) to avoid elimination from first place.
Here are the final standings in a scenario in which Houston finishes in first place with 39 wins:

Team             W	L	PCT	GB
Houston          39	123	0.241	0.00
Los Angeles      39	123	0.241	0.00
Texas            39	123	0.241	0.00
Oakland          39	123	0.241	0.00
Seattle          39	123	0.241	0.00

Tie breakers
Houston wins the series with Los Angeles 7 games to 6
Houston wins the series with Oakland 7 games to 6
Houston wins the series with Seattle 8 games to 5
Houston wins the series with Texas 10 games to 3

To construct the scenario, we start with the current standings in the division:
Team             W	L	GL	PCT	GB
Texas            20	16	126	0.556	0.0
Seattle          19	16	127	0.543	0.5
Oakland          17	19	126	0.472	3.0
Houston          12	22	128	0.353	7.0
Los Angeles      12	23	127	0.343	7.5

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

Houston currently has 0 win(s) against Los Angeles and 0 loss(es).
Houston wins 7 additional game(s) against Los Angeles and loses 6.
Houston wins the series 7 games to 6.
Houston wins 0 additional game(s) against teams outside the division and loses 86.

Houston currently has 0 win(s) against Oakland and 0 loss(es).
Houston wins 7 additional game(s) against Oakland and loses 6.
Houston wins the series 7 games to 6.
Houston wins 0 additional game(s) against teams outside the division and loses 86.

Houston currently has 1 win(s) against Seattle and 2 loss(es).
Houston wins 7 additional game(s) against Seattle and loses 3.
Houston wins the series 8 games to 5.
Houston wins 0 additional game(s) against teams outside the division and loses 86.

Houston currently has 4 win(s) against Texas and 3 loss(es).
Houston wins 6 additional game(s) against Texas and loses 0.
Houston wins the series 10 games to 3.
Houston wins 0 additional game(s) against teams outside the division and loses 86.

Los Angeles currently has 0 win(s) against Oakland and 0 loss(es).
Los Angeles wins 13 additional game(s) against Oakland and loses 0.
Los Angeles wins the series 13 games to 0.
Los Angeles wins 0 additional game(s) against teams outside the division and loses 75.

Los Angeles currently has 0 win(s) against Seattle and 0 loss(es).
Los Angeles wins 8 additional game(s) against Seattle and loses 5.
Los Angeles wins the series 8 games to 5.
Los Angeles wins 0 additional game(s) against teams outside the division and loses 75.

Los Angeles currently has 0 win(s) against Texas and 0 loss(es).
Los Angeles wins 0 additional game(s) against Texas and loses 13.
Los Angeles loses the series 0 games to 13.
Los Angeles wins 0 additional game(s) against teams outside the division and loses 75.

Oakland currently has 0 win(s) against Seattle and 0 loss(es).
Oakland wins 11 additional game(s) against Seattle and loses 2.
Oakland wins the series 11 games to 2.
Oakland wins 2 additional game(s) against teams outside the division and loses 76.

Oakland currently has 2 win(s) against Texas and 2 loss(es).
Oakland wins 3 additional game(s) against Texas and loses 6.
Oakland loses the series 5 games to 8.
Oakland wins 2 additional game(s) against teams outside the division and loses 76.

Seattle currently has 2 win(s) against Texas and 1 loss(es).
Seattle wins 10 additional game(s) against Texas and loses 0.
Seattle wins the series 12 games to 1.
Seattle wins 0 additional game(s) against teams outside the division and loses 81.

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