No. 1969.09.09 · Expansion Era
A Black Cat at Shea
A black cat walked in front of the Cubs' dugout at Shea. Chicago lost, 7–1. The standings, not the cat, are what the collapse was.
September 9, 1969, Shea Stadium, attendance 51,448. The Cubs led the National League East by a game and a half. On August 19 the lead had been eight games. Tom Seaver started for the Mets. Ferguson Jenkins started for Chicago. In the top of the fourth, with Glenn Beckert on second and Ron Santo in the on-deck circle, a black cat came onto the field, walked in front of the Cubs' dugout, and disappeared under the stands.
Santo said years later that the cat had looked at Leo Durocher. Ed Kranepool said Shea had a lot of rats, and therefore a lot of cats. After the cat left, Santo singled home the Cubs' only run. Seaver beat Jenkins, 7–1. Chicago's lead was down to half a game.
The Cubs went 8–17 in September. The Mets went 23–7 and clinched the division on September 24. Durocher's refusal to rest regulars is the explanation that shows up in the later accounts. The cat is the picture. It did not change the score.
Related entries
No. 1977.06.15
1977
Seaver to Cincinnati
On the night of the trading deadline, the Mets sent Tom Seaver to Cincinnati for four players, and Dave Kingman to San Diego in a separate deal.
New York Mets · Cincinnati Reds · San Diego Padres

The Bartman Game
Five outs from the World Series, a fan deflected a foul ball. The Cubs' shortstop then missed the double-play ball that would have ended the inning anyway.
Chicago Cubs · Florida Marlins
No. 1964.09.21
1964
The Phillies' 1964 Collapse
Philadelphia led the league by 6½ games with twelve to play. Gene Mauch kept running his aces out on short rest. The Phillies lost ten in a row.
Philadelphia Phillies · Cincinnati Reds · St. Louis Cardinals