Chicago does not have a first-place clinch number

Here is a scenario in which Chicago wins all 53 of their remaining games (105 total) but does not but does not clinch first place.

To construct the scenario, we start with the current standings in the division:
Team             W	L	GL	PCT	GB
Milwaukee        65	44	53	0.596	0.0
Cincinnati       57	51	54	0.528	7.5
St. Louis        53	54	55	0.495	11.0
Chicago          52	57	53	0.477	13.0
Pittsburgh       41	67	54	0.380	23.5

Next, we show how the remaining series of games in Chicago's division plays out in the scenario:

Chicago wins 6 games against Cincinnati and loses 0.
Chicago wins 7 games against Milwaukee and loses 0.
Chicago wins 7 games against Pittsburgh and loses 0.
Chicago wins 7 games against St. Louis and loses 0.
Chicago wins 26 games against teams outside the division and loses 0.

Cincinnati wins 0 games against Chicago and loses 6.
Cincinnati wins 3 games against Milwaukee and loses 0.
Cincinnati wins 13 games against Pittsburgh and loses 0.
Cincinnati wins 6 games against St. Louis and loses 0.
Cincinnati wins 26 games against teams outside the division and loses 0.

Milwaukee wins 0 games against Chicago and loses 7.
Milwaukee wins 0 games against Cincinnati and loses 3.
Milwaukee wins 3 games against Pittsburgh and loses 0.
Milwaukee wins 13 games against St. Louis and loses 0.
Milwaukee wins 27 games against teams outside the division and loses 0.

Pittsburgh wins 0 games against Chicago and loses 7.
Pittsburgh wins 0 games against Cincinnati and loses 13.
Pittsburgh wins 0 games against Milwaukee and loses 3.
Pittsburgh wins 10 games against St. Louis and loses 0.
Pittsburgh wins 21 games against teams outside the division and loses 0.

St. Louis wins 0 games against Chicago and loses 7.
St. Louis wins 0 games against Cincinnati and loses 6.
St. Louis wins 0 games against Milwaukee and loses 13.
St. Louis wins 0 games against Pittsburgh and loses 10.
St. Louis wins 19 games against teams outside the division and loses 0.

Combining the current standings with the wins and losses from the scenario results in the following final standings:
TEAM             W	L	GL	PCT
Milwaukee        108	54	0.667	0.0
Chicago          105	57	0.648	3.0
Cincinnati       105	57	0.648	3.0
Pittsburgh       72	90	0.444	36.0
St. Louis        72	90	0.444	36.0

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