Here are five of the most unlikely World Series winners in Major League Baseball history, based on various factors such as regular-season performance, team history, and playoff seeding:

1. 1914 Boston Braves: The Braves finished the regular season in fourth place in the National League but went on to sweep the Philadelphia Athletics in the World Series, becoming one of the biggest surprises.

2. 1969 New York Mets: The Mets had never finished above ninth place in their first seven seasons. They made a miraculous turnaround in 1969, winning the World Series against the heavily favored Baltimore Orioles.

3. 1987 Minnesota Twins: The Twins had a mediocre 85-77 record and were considered underdogs. They won a close seven-game series against the St. Louis Cardinals, becoming one of the least likely champions.

4. 2003 Florida Marlins: The Marlins finished the regular season with a 91-71 record but were not seen as serious contenders. They upset the New York Yankees in the World Series, marking their second championship in just their fifth season.

5. 2019 Washington Nationals: The Nationals had a rocky start to the season and were 19-31 in late May. They turned their season around, making a remarkable playoff run and defeating the Houston Astros in the World Series.

These teams defied expectations and made their mark in baseball history with their championship victories.