As upsets go in sports, baseball has long been known for its parity. Major League Baseball plays a season double the length of its closest rival the NBA. With 164 games spread across seven months, baseball enthusiasts appreciate that any team can beat another on any given day. However, when it turns October and its playoffs season, the landscape for upsets changes.

Short, five-game series have been known to produce an occasional win by the underdog. More often than not though, the best teams earn the right to move on. The ultimate stage for the MLB in the World Series. A seven-game slugfest, back and forth until one team wins the fourth game. Over the history of baseball, there have been a few times where the underdog prevailed.

The Unlikely Senators – 1924


The Senators, with abysmal recent history, went head-to-head with a team making its fourth consecutive appearance in the fall classic. Oddsmakers had the New York Giants as overwhelming favorites. Most felt that New York would potentially sweep the Senators.

This was not the case. New York would struggle during the middle games of the series. One win away from their third title in four tries, the Giants would ultimately be unable to close during game six. Washington would win during game seven and upset John McGraw’s highly-favored Giants.

Cincinnati Has a Bash – 1990


In 1990, there hadn’t been a World Series upset for over two decades. There wasn’t anyone who thought the Reds would change that trend against the Oakland A’s. Oakland had the charismatic Bash Brothers leading a cast of superstars.

In fact, the A’s were one of the top favorites in years; some fans projected a four-game sweep. It turned into a sweep alright, but for the underdog. Cincinnati was backed by an elite bullpen including a trio of relief pitchers known as the Nasty Boys.

They made the highest scoring team in the league that year look like befuddled little leaguers. Cincinnati’s pitching allowed Oakland a total of eight runs in four games, four of those in a 10-inning game. As heavily favored as Oakland was, the 1990 upset is deemed the biggest in World Series history.

Over the years there have been other World Series upsets. The young Florida Marlins franchise took out the legendary New York Yankees in 2003. Baseball purists will never forget how Pittsburgh Pirates second baseman Bill Mazeroski shocked the world with his ninth-inning walk-off home run in 1960.

The New York Mets defeat of the Baltimore Orioles in 1969 was considered an upset. However, the Mets actually won 100 games during that regular season. There have been a handful of World Series upsets out of the more than 100 Fall Classics. The improbable turnaround season of the 1924 Senators and the Reds stymieing of the 1990 Oakland A’s have to be two of the most memorable.