By September 2, they had a record of 84–52, well on pace to exceed the previous season's mark, but their lead over the Mets had fallen to five games.
The Cubs finished 92–70, while the Mets won the National League East and would go on to win the World Series.
Throughout the summer of 1969, led by future Hall of Famers Ernie Banks, Ferguson Jenkins, Ron Santo, Billy Williams, and the game calling skills of Randy Hundley behind the plate, the Chicago Cubs had built a substantial lead in the newly created National League East.
On opening day at Wrigley Field on April 8, the Cubs trailed the Phillies 6–5 in the bottom of the 11th inning.
The Cubs lost the final game of a series at Cincinnati, then came home to play the resurgent Pittsburgh Pirates (who would finish in third place).
But Willie Stargell drilled a 2-out, 2-strike pitch from the Cubs' ace reliever, Phil Regan, onto Sheffield Avenue to tie the score in the top of the ninth.
Burdened by a four-game losing streak, the Cubs traveled to Shea Stadium on September 8 for a short two-game set.
Disaster followed in Philadelphia, as a 99-loss Phillies team nonetheless defeated the Cubs twice, to extend Chicago's losing streak to eight games.
In a key play in the second game, on September 11, Cubs starter Dick Selma threw a surprise pickoff attempt to third baseman Ron Santo, who was nowhere near the bag or the ball.
[1] The Mets (who had lost a record 120 games in their inaugural season 7 years earlier), would go on to win the World Series.
The Cubs, despite a respectable 92–70 record, would be remembered for having lost a remarkable 17+1⁄2 games in the standings to the Mets in the last quarter of the season.
[7] The Book Baseball Hall of Shame 2 places the blame squarely (and perhaps unfairly) at the feet of one man, stating, "In the heat of battle, Leo Durocher, field general of the Cubs, went AWOL once too often.