The Colorado Rockies had a rough run during the 2025 MLB season. At the 50-game mark, they made history with the worst start in the modern MLB era. By September, they finished the season with the worst MLB record of the year: 43-119. At Coors Field, they finished 25-56, which marked the most home losses in franchise history. They also finished the season with the worst run differential in modern MLB history, at minus-424.
The Chicago White Sox struggled at an even worse historical level during the 2024 season. At the end of September, the White Sox broke the modern MLB era record for most losses in a season.
Check out the historical rundown below:
Worst Records, MLB History
(Min. 150 Games Played; W-L, Win Pct)
1899 Cleveland Spiders: 20-134, .130
1916 Philadelphia A's: 36-117, .235
1935 Boston Braves: 38-115, .248
1962 New York Mets: 40-120, .250
1904 Washington Senators: 38-113, .252
2024 Chicago White Sox: 41-121, .253
Most Losses in a Season, MLB History
(W-L, Win Pct)
1899 Cleveland Spiders: 134
2024 Chicago White Sox: 121
1962 New York Mets: 120
2003 Detroit Tigers: 119
2025 Colorado Rockies: 119
1916 Philadelphia Athletics: 117
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