Chicago Cubs First-Place Eliminiation Scenario
Chicago must win 7 more games (60 total) to avoid elimination from first place.
Here are the final standings in a scenario in which Chicago finishes in first place with 60 wins:

Team             W	L	PCT	GB
Chicago          60	102	0.370	0.00
Cincinnati       60	102	0.370	0.00
Pittsburgh       59	103	0.364	1.00
St. Louis        59	103	0.364	1.00
Milwaukee        59	103	0.364	1.00

Tie breakers
Chicago wins the series with Cincinnati 7 games to 6

To construct the scenario, we start with the current standings in the division:
Team             W	L	GL	PCT	GB
Chicago          53	35	74	0.602	0.0
Milwaukee        49	39	74	0.557	4.0
Cincinnati       46	41	75	0.529	6.5
St. Louis        47	42	73	0.528	6.5
Pittsburgh       38	51	73	0.427	15.5

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

Chicago currently has 4 win(s) against Cincinnati and 2 loss(es).
Chicago wins 3 additional game(s) against Cincinnati and loses 4.
Chicago wins the series 7 games to 6.
Chicago wins 0 additional game(s) against teams outside the division and loses 45.

Chicago currently has 3 win(s) against Milwaukee and 2 loss(es).
Chicago wins 0 additional game(s) against Milwaukee and loses 8.
Chicago loses the series 3 games to 10.
Chicago wins 0 additional game(s) against teams outside the division and loses 45.

Chicago currently has 5 win(s) against Pittsburgh and 2 loss(es).
Chicago wins 0 additional game(s) against Pittsburgh and loses 6.
Chicago loses the series 5 games to 8.
Chicago wins 0 additional game(s) against teams outside the division and loses 45.

Chicago currently has 3 win(s) against St. Louis and 2 loss(es).
Chicago wins 4 additional game(s) against St. Louis and loses 4.
Chicago wins the series 7 games to 6.
Chicago wins 0 additional game(s) against teams outside the division and loses 45.

Cincinnati currently has 2 win(s) against Milwaukee and 5 loss(es).
Cincinnati wins 6 additional game(s) against Milwaukee and loses 0.
Cincinnati wins the series 8 games to 5.
Cincinnati wins 0 additional game(s) against teams outside the division and loses 49.

Cincinnati currently has 4 win(s) against Pittsburgh and 2 loss(es).
Cincinnati wins 0 additional game(s) against Pittsburgh and loses 7.
Cincinnati loses the series 4 games to 9.
Cincinnati wins 0 additional game(s) against teams outside the division and loses 49.

Cincinnati currently has 3 win(s) against St. Louis and 4 loss(es).
Cincinnati wins 4 additional game(s) against St. Louis and loses 2.
Cincinnati wins the series 7 games to 6.
Cincinnati wins 0 additional game(s) against teams outside the division and loses 49.

Milwaukee currently has 4 win(s) against Pittsburgh and 3 loss(es).
Milwaukee wins 0 additional game(s) against Pittsburgh and loses 6.
Milwaukee loses the series 4 games to 9.
Milwaukee wins 0 additional game(s) against teams outside the division and loses 48.

Milwaukee currently has 4 win(s) against St. Louis and 3 loss(es).
Milwaukee wins 2 additional game(s) against St. Louis and loses 4.
Milwaukee loses the series 6 games to 7.
Milwaukee wins 0 additional game(s) against teams outside the division and loses 48.

Pittsburgh currently has 5 win(s) against St. Louis and 4 loss(es).
Pittsburgh wins 2 additional game(s) against St. Louis and loses 2.
Pittsburgh wins the series 7 games to 6.
Pittsburgh wins 0 additional game(s) against teams outside the division and loses 50.

# Chicago Cubs' magic number
# Chicago's magic number
# Cubs' magic number
# MLB Playoff Race