Which pitchers have the most strikeouts in MLB postseason history?

MLB's all-time postseason strikeout king is veteran right-hander Justin Verlander, which is interesting, because in a lot of ways the 40-year-old has been up and down in October. In 35 playoff outings he's posted a 3.64 ERA — well above his regular-season mark — but he's struggled significantly in the World Series, pitching to a 5.63 ERA in nine starts in the Fall Classic. That said, Verlander has obviously been a big part of two Astros championship teams, and the 230 batters he's punched out in 207.2 postseason innings are eye-opening. Barring a Houston collapse in September, he'll get a chance to add to his total next month. 

Verlander's career has run nearly parallel to that of Dodger's lefty Clayton Kershaw, and for a long time the duo were considered the best starting pitchers in their respective leagues. And similarly to Verlander, Kershaw for a while had a reputation of coming up short in October. His 4.22 playoff ERA is over a run and a half higher than his career mark in the regular season, and his 13-12 postseason record is not representative of the dominant ace he's been for a decade and a half in the big leagues. That said, Kershaw came up huge in three World Series starts in 2020 to earn his elusive first ring, and the 213 strikeouts he's tallied in 194 postseason innings are impressive. Like Verlander, he'll get a chance to add to that total in a few weeks. 

Thanks to being on a Braves team that simply dominated the National League East for more than a decade, righty John Smoltz got a chance to pitch in October essentially every season, and he really thrived on the postseason stage. In 41 playoff outings (27 starts), Smoltz worked to a dominant 2.67 ERA with a 1.14 WHIP, while striking out 199 hitters in 209 innings. He posted an impressive 15-4 playoff record, earned three saves, was the NLCS MVP in 1992, and helped Atlanta win the World Series in '95. 

Similar to Smoltz' situation with the Braves, lefty Andy Pettitte was nearly a yearly October participant thanks to pitching for a Yankees team that had more success than anyone else in the 1990s. During his career, Pettitte made 44 postseason starts, working to a 3.81 ERA with a 1.30 WHIP. He earned 19 victories, was the MVP of the 2001 ALCS, earned five World Series rings, and most relevant to this gallery, punched out 183 hitters. 

Big right-hander Roger Clemens was a teammate of Pettitte's for many years in the Bronx, and together the duo won World Series titles in 1999 and 2000. Clemens also pitched extensively in the playoffs for both the Red Sox and Astros during his career, and in total took the mound 35 times in the postseason. In those outings he pitched to a 3.75 ERA with 1.22 WHIP in 199 innings, while punching out 173 hitters to check in at number five on this list. 

Clemens' tenure in the top five in all-time postseason strikeouts is in significant jeopardy, however, due to who is currently in the sixth spot. Right-hander Max Scherzer fully expected to be pitching in October in 2023, but a season-ending injury dashed those hopes in brutal fashion. In the 23 postseason outings already on his resume, Scherzer has pitched to a 3.58 ERA across 133.1 innings, while striking out 164 batters, and he was instrumental in helping Washington win the World Series in 2019.

Hall of Fame righty Mike Mussina split his career nearly equally between Baltimore and the Bronx, and was clearly an impact hurler in both cities. Mussina won 270 games in his career, and actually raised his game in the postseason, pitching to a better ERA in October than during the regular season. Across 23 playoff outings he delivered a 3.42 ERA with a strong 1.10 WHIP in 139.2 innings, while punching out an impressive 145 batters. 

Thanks to all the years he spent in Atlanta, southpaw Tom Glavine had the good fortune of pitching in an astounding 24 different postseason series, and in fact, only Andy Pettitte has registered more playoff innings. In 35 career October starts, Glavine went 14-16 with a 3.30 ERA and a 1.27 WHIP, and while he wasn't particularly a strikeout pitcher, the 218.1 frames he tossed helped him accumulate 143 punchouts. 

Six-time all-star and 2019 American League ERA king Gerrit Cole has long been considered one of the elite pitchers in the game, but that hasn't always carried over into the postseason. Cole lost the 2015 NL Wild Card game while he was with the Pirates, and while for the most part he was brilliant for the Astros in October, since coming to the Bronx he's fired a couple of duds — most notably in the 2021 Wild Card game against Boston. Buoyed by his work in Houston, Cole's 2.93 playoff ERA across 17 starts is very good, but New York fans are anxious to see him lead them on the type of postseason run he did with the Astros. The 134 strikeouts he's registered in only 104.1 October innings do get your attention, though, and while it won't be this season, Yankees fans are hopeful he'll get another chance in the playoffs in the near future. 

Few pitchers have authored a postseason resume like southpaw Jon Lester, who won two World Series titles with the Red Sox and one with the Cubs, and was consistently able to elevate his game in the biggest contests. In 452 career regular-season outings Lester worked to a respectable 3.66 ERA, but he turned it up several notches in the playoffs, working to the tune of a 2.51 ERA with a 1.02 WHIP in 26 games. He was the MVP of the 2016 NLCS, and his team always felt confident with him on the mound in a big spot. In 154 October innings Lester struck out 133 hitters, which slots him just inside the top 10 all-time. 

Big left-hander Randy Johnson is one of the most heralded strikeout artists in baseball history, so it should come as no surprise whatsoever to see his name on this list. Johnson did not have as many postseason opportunities as some of the names ahead of him, pitching in only 19 playoff games and logging 121 innings. But he did predictably blow away 132 batters, and while his 3.50 lifetime postseason ERA isn't spectacular, he was otherworldly during the Diamondbacks' run to their 2001 World Series title, and was named the MVP of that Fall Classic. 

Hall of Fame righty Greg Maddux is obviously best known for his role in all the success the Atlanta Braves enjoyed in the 1990s, and while obviously most of his postseason work came in a Braves uniform, he did also make playoff starts for both the Cubs and the Dodgers. In 35 career October outings, Maddux pitched well, working to the tune of a 3.27 ERA with a 1.24 WHIP across 198 innings. He notched 11 victories, and most relevant to this list, recorded 125 outs by way of the K. 

The Cardinals are one of several high-profile veteran teams that have had endured incredibly disappointing 2023 campaigns, and for right-hander Adam Wainwright the season could not be going any worse. In 18 starts he's sporting an ERA over eight, and at 42 years old it certainly appears he's at the end of the line. That said, let's not forget how impactful he's been for St. Louis over the last 18 years. Wainwright was a huge part of the Cardinals' World Series win in 2006, and in 29 total playoff outings he was magnificent. In 114.1 innings, the Brunswick, GA native pitched to a stellar 2.83 ERA with a 1.11 WHIP, while striking out 123 hitters. 

Lefty CC Sabathia earned 251 wins in the major leagues, and spent the majority of his 19 seasons as a legitimate top-of-the-rotation starter in Cleveland, Milwaukee, and New York. The vast majority of his postseason work came in a Yankees uniform, though he often delivered mixed results in October. In 26 total playoff appearances he pitched to a 4.28 ERA in 130.1 innings. His 1.53 postseason WHIP was well above his career regular-season mark, but he did strike out 121 batters and, most importantly, play a key role in the Yankees' 2009 World Series title. 

To this day, right-hander Curt Schilling is remembered as one of the most dominant postseason pitchers of his era, and the Anchorage, AK native certainly has the jewelry to show for it. Schilling made playoff starts for the Phillies, Diamondbacks, and Red Sox, and was downright brilliant for every one of them. In 19 cumulative October outings, Schillinh went 11-2 with an eye-opening 2.23 ERA and a 0.97 WHIP. He fired four complete games, struck out 120 hitters in 133.1 innings, and most importantly was the driving force behind two World Series championships in Boston and one in Arizona. 

Next up on the list is perhaps an unknown name to a lot of people reading this: left-hander Bill Foster. The Calvert, TX native was one of the most accomplished hurlers in Negro League history, winning four ERA titles and helping the Chicago American Giants win two World Series championships. In 25 postseason outings (19 starts), he earned 12 wins while pitching to a 2.54 ERA with a 1.26 WHIP. He threw 17 complete games in the playoffs — including three shutouts — and punched out 116 hitters in 170.1 innings of work. The Veterans Committee voted Foster into the Hall of Fame in 1996. 

Righty John Lackey holds the rare distinction of being one of the only pitchers to win World Series rings with three different teams; in his case, the Angels, Red Sox, and Cubs. As you'd expect from that tidbit, Lackey was no stranger to the month of October during his career, taking the mound 29 different times in the postseason. In those outings he wasn't exactly lights out, pitching to a 3.44 ERA and a 1.31 WHIP across 144 frames, but he did strike out 114 hitters in the process. 

Mariano Rivera is the only pure relief pitcher on this list, which in itself is representative of just how dominant he really was. Pitching for the Yankees granted the righty a plethora of postseason opportunities, and nearly every time his name was called he was ready to answer the bell. In 96 October outings, Rivera pitched to a spectacular 0.70 ERA with a 0.76 WHIP. He converted 42 postseason saves, earned eight victories, and was named the MVP of both the 1999 World Series and the 2003 ALCS. He also struck out 110 hitters in 141 innings, landing him 18th on the all-time postseason strikeout list. 

Cuban-born Orlando "El Duque" Hernandez was a solid big league pitcher during his nine seasons in the major leagues, but when the calendar flipped to October he consistently seemed to morph into a folk hero. In 19 playoff outings, Hernandez pitched to a 2.55 ERA — a stark contrast from his 4.13 regular-season mark. He earned nine postseason victories, struck out 107 hitters in only 106 innings, and won three World Series titles with the Yankees, as well as one with the White Sox. 

Righty Walker Buehler was an incredibly productive top-of-the-rotation starter for the Dodgers from 2018-22, and the team has really felt his absence this season as he recovers from Tommy John surgery. Buehler qualified for two all-star teams, helped the Dodgers win the 2020 World Series, and has an impressive 46-16 career record. The team is hopeful he can return late this year and perhaps pitch in October, though that is far from guaranteed. That would be a huge boon for Los Angeles, however, as in the first 15 postseason outings of his career he's pitched to a 2.94 ERA and struck out 101 hitters in 79.2 innings. 

Righty Zack Greinke has made postseason starts for the Brewers, Diamondbacks, Dodgers, and Astros, but the month of October has not always been kind to the likely future Hall of Famer. In 22 career playoff outings, he's worked to a 4.14 ERA — up significantly from his 3.49 regular-season mark — and he owns just a 4-6 postseason record. Greinke has been adept at putting hitters away with strikeouts, though, notching 100 in 113 playoff innings.