Most Strikeouts in an MLB Game: Inside the 20-K Club and Why It May Never Be Broken

Twenty-four pitchers have thrown a perfect game. Only four have struck out 20 batters in nine innings. That gap is the fastest way to understand where the single-game strikeout record sits in baseball’s hierarchy of hard things — and why nobody has touched it since 2016.

Key Takeaways

• Four pitchers have struck out 20 in nine innings, across five total games. Roger Clemens did it twice.
• Tom Cheney holds the outright single-game record with 21, but it took him 16 innings and 228 pitches in 1962.
• Kerry Wood’s 1998 one-hitter produced a Game Score of 105 — the highest ever for a nine-inning start.
• Hideo Nomo’s 17 strikeouts in 1996 remain the high-water mark for a Japanese pitcher in MLB.
• Strikeout rates keep climbing, but pitch counts have made the 20-K game structurally harder than it was in 1986.

The 20-Strikeout Club

Pitcher	Date	Matchup	K	Result
Roger Clemens	April 29, 1986	Red Sox vs. Mariners	20	Complete-game win
Roger Clemens	Sept. 18, 1996	Red Sox vs. Tigers	20	Complete-game shutout
Kerry Wood	May 6, 1998	Cubs vs. Astros	20	Complete-game shutout
Randy Johnson	May 8, 2001	Diamondbacks vs. Reds	20	Exited after 9; game went extra innings
Max Scherzer	May 11, 2016	Nationals vs. Tigers	20	Complete-game win

Cheney’s 21 sits in a separate category, and the reason is density rather than snobbery. Twenty strikeouts in nine innings is 2.22 per inning. Twenty-one across 16 innings is 1.31. Those are different achievements, so MLB tracks the nine-inning mark and the all-innings mark separately.

Roger Clemens Did It Twice, a Decade Apart

Clemens was 23 and coming off shoulder surgery when he faced the Seattle Mariners on April 29, 1986. He struck out 20 of the 30 batters he faced, walked nobody, allowed three hits and one run, and went the distance. It was the first 20-strikeout game in major league history and it arrived from a pitcher scouts had been quietly writing off.

On Sept. 18, 1996 — still with Boston, now 34 — he did it again against the Detroit Tigers, this time a shutout. No other pitcher has reached 20 even once in nine innings and lived to repeat it.

Clemens finished with seven Cy Young Awards. The two 20-strikeout games bracket the decade in which he was the most overpowering right-hander alive.

Kerry Wood’s 1998 Game Is the Best of the Five

Wood was 20 years old, a Chicago Cubs rookie making his fifth career start, when he faced the Houston Astros on May 6, 1998.

The line: one hit, no walks, one hit batsman, 20 strikeouts. He needed 122 pitches, 84 for strikes, and the whole thing took 2 hours, 19 minutes. The Astros lineup he dismantled included future Hall of Famers Craig Biggio and Jeff Bagwell plus Moisés Alou — not a soft target.

By Game Score, Bill James’ composite measure of innings, hits, runs, walks and strikeouts, Wood’s outing rates 105. That is the highest figure ever recorded for a nine-inning start. By that metric, the best start in baseball history belongs to a 20-year-old rookie.

Wood won NL Rookie of the Year that season. Arm injuries then took the career that game seemed to promise. The start survives anyway.

Randy Johnson’s Asterisk Is Not Really an Asterisk

Johnson was 37 on May 8, 2001, when he struck out 20 Cincinnati Reds over nine innings and handed the ball to his bullpen. The game went to extras, so he left without a decision.

That is the only thing separating his outing from the other four. Nine innings, 20 strikeouts, fastball and slider, the same as anyone else on the list. The Big Unit went on to win a World Series with Arizona that fall and reach Cooperstown after retiring.

Max Scherzer Was One Away From the Outright Record

Scherzer carried 18 strikeouts into the ninth inning against Detroit on May 11, 2016.

Then J.D. Martinez led off with a solo home run. Scherzer struck out Miguel Cabrera swinging for No. 19, gave up a single to Victor Martinez, and struck out Justin Upton swinging for No. 20. James McCann, the last batter, grounded out. One more whiff and Scherzer would own the nine-inning record outright.

He needed only 119 pitches — the most efficient of the five 20-strikeout games.

The 19-Strikeout Near-Misses

The list of pitchers who got to 19 and stopped is its own Hall of Fame wing: Steve Carlton (1969), Tom Seaver (1970), Nolan Ryan (1974), David Cone (1991) and Johnson, who did it twice in 1997 before finally reaching 20 four years later.

Tom Cheney Pitched 16 Innings for 21 Strikeouts

On Sept. 12, 1962, Cheney of the Washington Senators went all 16 innings against the Baltimore Orioles, threw 228 pitches and struck out 21 in a 2-1 win. It is still the most strikeouts by one pitcher in a major league game.

Manager Mickey Vernon asked repeatedly whether he wanted out. Cheney later recalled his answer: “I told him I didn’t want to come out. Back in those days, you finished what you started.”

That sentence is the record’s real context. There was no pitch count because the concept barely existed. Today an elite starter is managed to roughly 100 to 115 pitches, which makes 228 not merely unlikely but organizationally impossible. Cheney’s record is safe because the sport that produced it no longer exists.

The Japanese Pitchers Who Came Closest

Pitcher	K	Date	Opponent
Hideo Nomo	17	April 13, 1996	Marlins
Yu Darvish	15	Aug. 12, 2013	Astros
Masahiro Tanaka	15	Sept. 29, 2017	Blue Jays
Shohei Ohtani	13	June 22, 2022	Royals
Shohei Ohtani	13	May 3, 2023	Cardinals

Hisashi Iwakuma, Kenta Maeda and Yusei Kikuchi have also reached 13, Kikuchi most recently against the Giants on July 9, 2024.

Nomo’s 17 against the Florida Marlins on April 13, 1996, is the mark to beat. It came during the stretch when “Nomomania” was reshaping how American hitters thought about Japanese pitching. His fastball was legitimate, but the splitter was the problem — it entered the zone and left it, and MLB hitters of that era had seen nothing quite like it. Swings at pitches nowhere near the strike zone were the engine of that game.

Darvish’s career high of 15 came with Texas in 2013. His approach is the opposite of Nomo’s: six or seven usable pitches and a willingness to attack differently every time through the order. His strikeout rate in put-away counts is elite. Stacking 20 in one outing, though, requires the lineup to cooperate for all nine innings.

Ohtani sits at 13, and the ceiling is structural rather than physical. Two-way usage caps how deep he goes and how many pitches he throws in a start, which removes the back-end innings where a 20-strikeout game is actually won. In 2026 he made 14 starts with a 1.79 ERA — by ERA and WHIP the best pitching of his career — over 85 2/3 innings with 95 strikeouts and an 8-2 record.

Will Anyone Reach 20 Again?

Two trends are pulling in opposite directions.

Strikeouts keep rising. Velocity is up, breaking balls are better and more varied, and hitters swing harder in exchange for contact. Leaguewide strikeout rates have set records repeatedly since the 2010s. Fifteen-strikeout starts are more common than they were.

Complete games are nearly extinct. Starters come out around 100 to 115 pitches. The most efficient 20-strikeout game ever still took 119. Getting 20 means striking out roughly two-thirds of the 30 batters you face, and strikeouts are the most expensive outs available — three pitches minimum, often six or seven. The pitch count arrives before the 20th strikeout does.

That is the squeeze. The skill needed is more common than ever; the opportunity is rarer than ever.

The closest anyone has come since Scherzer is Chris Sale, who struck out 17 Rockies on May 14, 2019 — in seven innings. It was the first 17-strikeout game since Scherzer’s and the first ever in seven innings or fewer. Even then, three short.

Paul Skenes of the Pirates and Tarik Skubal, the two-time Cy Young winner the Dodgers acquired from Detroit at the 2026 deadline, both miss bats at rates that make 20 conceivable. Conceivable is doing a lot of work in that sentence. It requires a pitcher’s best stuff, a lineup willing to chase, a manager willing to let him finish, and a low enough pitch count to make that defensible — all on the same afternoon.

Why 20 Still Means Something

The 20-strikeout game is not purely a measure of talent. It needs the pitcher’s best day, the right opponent, a cooperative game script and a ballpark that helps. Clemens, Wood, Johnson and Scherzer each got all of it at once.

That is the appeal. The record is not waiting on someone good enough — several pitchers are already good enough. It is waiting on a day when everything lines up. Which is why the wait has lasted a decade, and why it is still worth watching for.