Who Has the Best ERA in MLB Playoff History?

The list of the 20 players with the best career postseason ERA stretches from Cy Young in the 19th century to modern-day October stars.

Baseball is constantly evolving, but a dominant pitcher in the postseason is always a factor to consider when evaluating World Series odds. An ace can put a team on his back like Madison Bumgarner did in 2014, while a shutdown reliever can swing a series with vital outs in high-leverage situations. 

20 Best Career Postseason Earned Run Averages

Mariano Rivera has the lowest ERA in MLB postseason history. Rivera’s 141 innings are 39.2 ahead of anyone else on this list. 

Christy Mathewson is the only other pitcher to have logged more than 100 innings and rank in the top 20 in ERA (of pitchers with 30+ postseason innings).

Of course, Rivera was part of a New York Yankees dynasty. Baseball odds had the Yankees at a short price to win the World Series throughout Rivera’s career. He only missed the playoffs twice, which helped him collect 42 saves. Kenley Jansen is second on the postseason saves list with 20. 

Three-time World Series winner Jeremy Affeldt makes it two relievers in the top three. 

Affeldt was part of the San Francisco Giants’ core four bullpen (along with Santiago Casilla, Sergio Romo, and Javier López) during their run of three titles in five years. He was on the mound when Joe Panik and Brandon Crawford turned their spectacular double play in Game 7 of the 2014 World Series.

“The golden era of San Francisco baseball does not happen without Romo, López, Affeldt, and Casilla.” pic.twitter.com/iMfAkZLEYd

— SFGiants (@SFGiants) July 13, 2024

Andrew Miller joins Affeldt as a lefty reliever with a playoff ERA below 1.00. Miller was at his best for Cleveland in 2016, which included winning the 2016 ALCS MVP. 

Ninth on the list, Monte Pearson made four postseason starts, resulting in four consecutive World Series wins (1936-39) for the New York Yankees. Pearson pitched three complete games and allowed just 19 hits across 35.2 innings. Despite being a dominant pitcher in the Fall Classic, he was only a two-time All-Star. 

Clay Carroll was a key reliever for the Big Red Machine in the 1970s. He had a cWPA of more than 25% in the 1975 World Series but was traded to the Chicago White Sox that December. 

Despite a 1.26 playoff ERA with 40 strikeouts in 35.2 innings, Ian Anderson did not pitch in the majors in 2023 or 2024. However, he pitched five no-hit innings against the Houston Astros in the 2021 World Series.