Arizona Diamondbacks First-Place Elimination Scenario
Arizona must win 8 more games (85 total) to avoid elimination from first place.
Here are the final standings in a scenario in which Arizona finishes in first place with 85 wins:

Team             W	L	PCT	GB
Arizona          85	77	0.525	0.00
Los Angeles      85	77	0.525	0.00
San Diego        84	78	0.519	1.00
San Francisco    80	82	0.494	5.00
Colorado         45	117	0.278	40.00

Tie breakers
Arizona wins the series with Los Angeles 8 games to 5

To construct the scenario, we start with the current standings in the division:
Team             W	L	GL	PCT	GB
Los Angeles      85	67	10	0.559	0.0
San Diego        83	69	10	0.546	2.0
Arizona          77	76	9	0.503	8.5
San Francisco    76	76	10	0.500	9.0
Colorado         41	111	10	0.270	44.0

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

Arizona currently has 8 win(s) against Colorado and 5 loss(es).
Arizona and Colorado have no remaining games.
Arizona wins the series 8 games to 5.
Arizona wins 2 additional game(s) against teams outside the division and loses 1.

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

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

Arizona currently has 7 win(s) against San Francisco and 6 loss(es).
Arizona and San Francisco have no remaining games.
Arizona wins the series 7 games to 6.
Arizona wins 2 additional game(s) against teams outside the division and loses 1.

Colorado currently has 2 win(s) against Los Angeles and 11 loss(es).
Colorado and Los Angeles have no remaining games.
Colorado loses the series 2 games to 11.
Colorado wins 1 additional game(s) against teams outside the division and loses 6.

Colorado currently has 3 win(s) against San Diego and 10 loss(es).
Colorado and San Diego have no remaining games.
Colorado loses the series 3 games to 10.
Colorado wins 1 additional game(s) against teams outside the division and loses 6.

Colorado currently has 2 win(s) against San Francisco and 8 loss(es).
Colorado wins 3 additional game(s) against San Francisco and loses 0.
Colorado loses the series 5 games to 8.
Colorado wins 1 additional game(s) against teams outside the division and loses 6.

Los Angeles currently has 9 win(s) against San Diego and 4 loss(es).
Los Angeles and San Diego have no remaining games.
Los Angeles wins the series 9 games to 4.
Los Angeles wins 0 additional game(s) against teams outside the division and loses 3.

Los Angeles currently has 6 win(s) against San Francisco and 3 loss(es).
Los Angeles wins 0 additional game(s) against San Francisco and loses 4.
Los Angeles loses the series 6 games to 7.
Los Angeles wins 0 additional game(s) against teams outside the division and loses 3.

San Diego currently has 10 win(s) against San Francisco and 3 loss(es).
San Diego and San Francisco have no remaining games.
San Diego wins the series 10 games to 3.
San Diego wins 1 additional game(s) against teams outside the division and loses 6.

# Arizona Diamondbacks' magic number
# Arizona's magic number
# Diamondbacks' magic number
# MLB Playoff Race