Chicago Cubs First-Place Clinch Scenario

Chicago's traditional magic number (relative to second-place Milwaukee) is 53 + 69 - 54 + 1 = 69.
Chicago's first-place clinch number is 66.
Chicago must win 66 more games (120 total) to clinch first place.

If Chicago wins 66 more games, their final win total will be at least 120.
The table below shows the best case scenario for each of the other teams if Chicago wins 66 of their remaining 70 games and loses the other 4.
For each team, the table shows the current record (number of wins (W) and losses (L)) and the number of games that team has
left to play (GL) in the regular season. Taking the schedule of games left to play into account, the 'Losses to Chicago' column gives the
minimum number of games that each team will lose to Chicago if Chicago wins 66 more games. Assuming that a team wins all of its remaining games except for
the games it loses to ChicagoCubs, the resulting maximum number of wins is shown in the 'Maximum W' column.

Team             W	L	GL	Losses to Chicago	Maximum W
Milwaukee        53	40	69	       8 - 4 = 4	118
St. Louis        49	44	69	       6 - 4 = 2	116
Cincinnati       47	46	69	       7 - 4 = 3	113
Pittsburgh       38	56	68	       6 - 4 = 2	104

The table above shows that if Chicago wins 66 more games (120 total), then they will finish the season in first place in the division.

To see that Chicago's first-place clinch number cannot be less than 66, consider the following scenario in which Chicago wins 65 more games (119 total) but does not finish in first place:

Team             W	L	PCT	GB
Milwaukee        119	43	0.735	0.00
Chicago          119	43	0.735	0.00
St. Louis        77	85	0.475	42.00
Cincinnati       73	89	0.451	46.00
Pittsburgh       54	108	0.333	65.00

Tie breakers
Milwaukee wins the season series with Chicago 7 games to 6.

To construct the scenario, we start with the current standings in the division:
Team             W	L	GL	PCT	GB
Chicago          54	38	70	0.587	0.0
Milwaukee        53	40	69	0.570	1.5
St. Louis        49	44	69	0.527	5.5
Cincinnati       47	46	69	0.505	7.5
Pittsburgh       38	56	68	0.404	17.0

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


Chicago currently has 4 wins against Cincinnati and 2 losses.
  Chicago wins 7 additional games against Cincinnati and loses 0.
  Chicago wins the series 11 games to 2

Chicago currently has 5 wins against Pittsburgh and 2 losses.
  Chicago wins 6 additional games against Pittsburgh and loses 0.
  Chicago wins the series 11 games to 2

Chicago currently has 4 wins against St. Louis and 3 losses.
  Chicago wins 6 additional games against St. Louis and loses 0.
  Chicago wins the series 10 games to 3

Cincinnati currently has 4 wins against Pittsburgh and 2 losses.
  Cincinnati wins 6 additional games against Pittsburgh and loses 1.
  Cincinnati wins the series 10 games to 3

Milwaukee currently has 2 wins against Chicago and 3 losses.
  Milwaukee wins 5 additional games against Chicago and loses 3.
  Milwaukee wins the series 7 games to 6

Milwaukee currently has 5 wins against Cincinnati and 2 losses.
  Milwaukee wins 6 additional games against Cincinnati and loses 0.
  Milwaukee wins the series 11 games to 2

Milwaukee currently has 4 wins against Pittsburgh and 3 losses.
  Milwaukee wins 6 additional games against Pittsburgh and loses 0.
  Milwaukee wins the series 10 games to 3

Milwaukee currently has 4 wins against St. Louis and 3 losses.
  Milwaukee wins 6 additional games against St. Louis and loses 0.
  Milwaukee wins the series 10 games to 3

Pittsburgh currently has 5 wins against St. Louis and 4 losses.
  Pittsburgh wins 3 additional games against St. Louis and loses 1.
  Pittsburgh wins the series 8 games to 5

St. Louis currently has 4 wins against Cincinnati and 3 losses.
  St. Louis wins 6 additional games against Cincinnati and loses 0.
  St. Louis wins the series 10 games to 3

Chicago wins 43 games agains teams outside the division and loses 0.
Cincinnati wins 20 games agains teams outside the division and loses 23.
Milwaukee wins 43 games agains teams outside the division and loses 0.
Pittsburgh wins 12 games agains teams outside the division and loses 33.
St. Louis wins 21 games agains teams outside the division and loses 26.

Combining the current standings with the wins and losses from the scenario results in the final standings listed above.
# Chicago Cubs' magic number
# Chicago's magic number
# Cubs' magic number
# MLB Playoff Race