As of August 2025, the Colorado Rockies have a run differential of -316 for the 2025 MLB season. Their 114 games are the fewest to reach a -300 run differential since 1900, surpassing the 1911 Boston Rustlers (118 games). The last team to reach the mark in fewer games was the 1899 Cleveland Spiders, who did so in 73 games before folding at the end of the season.
The Chicago White Sox struggled at a similar historical level throughout the full duration of 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
1916 Philadelphia Athletics: 117
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