The Worst Record in MLB History

The worst record in MLB history is 20-134, posted by the 1899 Cleveland Spiders — a .130 winning percentage across 154 games. No team before or since has come close.

But “worst record” splits into three separate records depending on how you frame it, and most pages that answer this question pick one and never say which. Here is the honest version.

From the scorebook — All-time worst: 1899 Cleveland Spiders, 20-134 (.130). Modern-era worst by percentage: 1916 Philadelphia Athletics, 36-117 (.235). Most losses ever: 2024 Chicago White Sox, 121.

The all-time worst: 1899 Cleveland Spiders (20-134)

The Spiders did not lose 134 games because they were unlucky. They lost because their own owners took the team apart on purpose.

The Robison brothers owned Cleveland and, in early 1899, bought the St. Louis Browns as well. Owning two clubs in the same league was legal then. So they moved Cleveland’s best players — including future Hall of Famers Cy Young, Jesse Burkett and Bobby Wallace — to St. Louis, renamed that club the Perfectos, and left Cleveland with whatever was left over.

What followed is the most complete collapse in the sport’s records:

• 20-134, a .130 winning percentage
• 9-33 at home, 11-101 on the road — a .098 road winning percentage
• 529 runs scored, 1,252 allowed, a run differential of −723
• 6,088 total home attendance across the season, roughly 145 people a game
• A 24-game losing streak from late August into September

Home attendance collapsed so completely that other clubs stopped wanting to travel to Cleveland at all, which is why the Spiders played 112 of their 154 games on the road. The team was dissolved after the season when the National League cut from twelve clubs to eight.

This is why the Spiders sit outside most “worst ever” conversations even though they own the number. The 1899 season had no reserve-clause parity, no draft, no revenue sharing, and no rule against one owner controlling two teams. The record is real, and it is also a record about ownership rather than about baseball.

The modern-era worst: 1916 Philadelphia Athletics (36-117)

MLB’s modern era starts in 1901, when the American League joined the National League. Every record from 1901 forward is measured against a stable two-league structure, which is why writers separate it out.

The lowest winning percentage of that entire era belongs to the 1916 Philadelphia Athletics at 36-117, a .235 winning percentage. Connie Mack had sold off most of his stars after the 1914 World Series, and the 1916 club finished 40 games behind the next-worst team in the league — a gap larger than the one between first and last place in most modern divisions.

That .235 mark has stood for more than a century. It survived the 1962 Mets. It survived the 2024 White Sox by twelve thousandths of a point.

The most losses ever: 2024 Chicago White Sox (121)

The 2024 Chicago White Sox finished 41-121, breaking the 1962 New York Mets’ record of 120 losses that had stood for 62 years. Their run differential was −306, worst in baseball that year.

Here is the part that gets lost. The White Sox lost more games than the Mets, but they also won one more, and they played two more games. By winning percentage the 2024 White Sox (.253) were marginally better than the 1962 Mets (.250). Both are worse than the 1916 Athletics.

More losses does not mean a worse team. It can just mean a longer season.

Worst records, ranked properly

Team	Record	Win %	Era	What it holds
1899 Cleveland Spiders	20-134	.130	Pre-1900 NL	Worst record of all time
1890 Pittsburgh Alleghenys	23-113	.169	Pre-1900 NL	Second-worst all time
1889 Louisville Colonels	27-111	.196	American Association	Third-worst all time
1916 Philadelphia Athletics	36-117	.235	Modern	Worst win % since 1901
1935 Boston Braves	38-115	.248	Modern	Second-worst win % since 1901
1962 New York Mets	40-120	.250	Modern, expansion	Held loss record 62 years
2024 Chicago White Sox	41-121	.253	Modern, 162-game	Most losses in MLB history
2003 Detroit Tigers	43-119	.265	Modern, 162-game	Tied for third-most losses
2025 Colorado Rockies	43-119	.265	Modern, 162-game	Most NL losses of the divisional era

Read the era column before you read the record column. A 154-game season and a 162-game season are not the same measuring stick, and a pre-1900 National League with twelve teams and syndicate ownership is a different sport in every way that matters to a standings table.

Why season length breaks the comparison

The 1916 Athletics played 153 games. The 2024 White Sox played 162. Nine extra games is nine extra chances to lose, which is exactly why the loss record keeps moving while the winning-percentage record does not.

MLB’s schedule has been 162 games since 1961 in the American League and 1962 in the National League. Before that it was 154. Before 1904 it varied year to year. Any “most losses” record is therefore biased toward recent teams, and any “worst percentage” record is biased toward eras where competitive balance did not exist.

The clean rule: use winning percentage to compare quality across eras, and use raw losses only within the same schedule length.

What this looks like from the other end

The exact inverse of this page is the sport’s most famous impossibility. No team has come close to a perfect year, and the reasons are the same reasons the Spiders exist — baseball’s daily grind punishes any structural weakness over 162 games, in either direction. For the winning side of the ledger, see the best single-season records in MLB history and why no MLB team wins more than 116.

The floor and the ceiling are further apart than most fans assume. The best modern team wins about 72% of its games. The worst modern team wins about 24%. Neither end gets anywhere near the extremes, which is what makes 162-0 effectively impossible — and 0-162 just as unreachable from below.