What Is a Strikeout in Baseball? Historical Rates & Records

Youth baseball pitcher in blue and yellow gets the batter in blue and red to swing at a pitch outside the strike zone.

A whiff, a punchout, or a K. Whatever you call it, they’re referring to the same thing, which is a play in baseball we’re seeing more often than ever before and more than any other play: the strikeout.

Strikeouts are one of the most basic and cut-and-dry plays in baseball and a first step in understanding baseball as a whole.

So, what is a strikeout in baseball?

A strikeout occurs when a batter fails to hit three strikes in the span of one at bat, whether those are called strikes, swinging strikes, foul balls, or some combination of the three. A batter may strike out swinging or looking, but can’t strikeout on a foul ball.

Strikeouts are a way many fans measure how overpowering certain pitchers can be. Likewise, a hitter may be considered poor if he strikes out a lot. But there’s more to it than just that – so let’s dive in.

How Does a Batter Get a Strike?

Now, chances are you know the term, “three strikes and you’re out,” which is exactly the case in baseball (with one exception, but we’ll save that for later).

The question is exactly what constitutes a strike?

A batter is assessed a strike whenever he does not swing at a pitch that is judged to be in the strike zone by the home plate umpire, swings and misses at a pitch in any location or hits a foul ball.

To quickly summarize the difference between these three, a pitch in the strike zone that is not swung at is known as a called strike.

At the major league level, the strike zone is generally defined as any part over home plate between the batter’s knees and just above his belt line. Strike zones vary differently at lower levels.

Any pitch within the judged area is a strike, while anything outside of it that is not swung at is considered a ball. While three strikes is an out, on the other side of the coin, if a hitter draws four balls in an at-bat, then he goes to first base by way of a base-on-balls, which is commonly referred to as just a walk.

A swing and a miss (known as a swinging strike) is the most self-explanatory of the three. If you swing the bat and hit nothing, that’s a swinging strike, plain and simple.

As for a foul ball, this is a pitch that you swing and make contact with, but do not hit in between the two white foul lines extending down the first and third baselines. Foul balls are different in that a batter can earn his first two strikes on foul balls, but cannot strike out on a foul ball unless the player bunts the ball foul.

For a strikeout to occur, any combination of these three occasions may happen. A batter may swing and miss three straight pitches, take three called strikes, or swing and miss twice, hit a foul ball, take a ball, hit another foul, take another ball, foul off six more pitches, take a third ball, foul off six more pitches, then swing and miss for strike three.

Yes, that actually happened.

The point is, there is an infinite number of combinations that ultimately result in three strikes on the hitter.

Is a Batter Always Out on a Strikeout?

A Los Angeles Dodgers pitcher during his delivery home.

Earlier, we mentioned the “three strikes and you’re out” phrase, which seems rather cut-and-dry. Indeed, when a batter is assessed three strikes any which way, it is automatically a strikeout. However, in certain situations, it is not a guaranteed out.

How so? Well, glad you asked.

On strike three, the catcher must catch the ball cleanly (whether it be a swinging or called strike) before it hits the ground. If the ball hits the ground before being caught and first base is unoccupied, or there’s two outs in the inning, the batter may reach on a dropped third strike.

With the dropped third strike rule, parameters are set outlining situations in which the rule applies. If a runner is on first base with less than two outs (regardless of whether there are any runners ahead of him), the rule does not apply. If there is no runner on first with any number of outs, the rule applies.

Likewise, with two outs, all situations require strike three to be secured.

In most cases, a dropped third strike is a pitch in the dirt that the batter is fooled on and swings and misses at. In that case, the ball usually bounces and is either blocked by the catcher or rolls away.

Once the catcher retrieves the ball, he may either tag the batter or throw to first base. If the bases are loaded with two outs, the catcher may simply touch home plate with possession of the ball to record the third out as well.

However, if the catcher fails to accomplish either task or if his throw to first base is beaten by the batter, then the batter reaches base safely. The play is scored is a strikeout and a wild pitch. The pitcher will still earn credit for the strikeout and the batter will still have the strikeout on his stat line as well, but the batter will be on first base.

In lower levels of baseball where catchers are not as well developed and batters are less disciplined, dropped third strikes are more common, but in professional baseball, they are not. From 2016-20, there were nearly 179,000 strikeouts in Major League Baseball and only 486 resulted in the batter reaching first base.

In other words, about 1 out of 368 (or just 0.272%) strikeout victims will reach first base at the MLB level. That said, a dropped third strike occurs just often enough to cause a few statistic oddities.

Most notably, sometimes a pitcher will strike out four batters in one inning (to earn three outs), which has occurred 88 times in Major League Baseball through the 2020 season, with four accomplishing the feat twice (Chuck Finley did it three times).

At least six minor league pitchers are known to have recorded a five-strikeout inning, though this has not yet occurred at the sport’s highest level.

In summary, a batter may get lucky once in a blue moon and earn a trip to first base despite striking out, but it’s a rare enough occurrence that hitters probably shouldn’t bank on reaching on a dropped third strike very often.

What Is a “K” in Baseball?

In the open, we mentioned three terms that are often used as slang for strikeouts: whiffs, punchouts, and K’s. The first two make sense, as a strikeout often occurs on a swing and a miss, or a whiff. Likewise, a strikeout on a called third strike (or a strikeout looking) sees the batter being called out, or punched out, by the umpire.

As for a “K,” well what is that?

A “K” is another term for a strikeout, which is derived from the predominant letter in the word “strike.” The use of the letter K is primarily for shorthand purposes, such as keeping score, where space is limited. In scorekeeping shorthand, a backward K is used when a batter strikes out looking.

So why the letter K?

Well, over 150 years ago, back when baseball first gained popularity in the 1860s, sportswriter Henry Chadwick devised the basics for many baseball statistics which are still in use today, which includes the box score. Along with that, he also developed a shorthand lexicon still in use today for scorekeeping purposes, including position numbers.

He also used one or two-letter abbreviations for plays, such as HR for home run and SB for stolen base. He chose K for a strikeout since he used the letter “S” for a sacrifice already (though SAC and SF have since supplanted that).  

It’s unclear whether Chadwick was also responsible for this, but somewhere along the way, a backward K became the standard for a strikeout looking. Writing it down isn’t a problem, but translating the term to modern technology is…a little tricky.

Because there’s no cut-and-dry method readily available for typing a backward K, the best way to type one is probably to just search for a backward K online and copy-and-paste it, ending up with something like this: ꓘ.

That said, a popular place to find the use of the K besides writing it on a scorecard is at the ballpark, as many teams have strikeout or “K counters” in use, both in official and unofficial capacities. For some fans, it’s a fun way to track how many strikeouts their team’s pitcher (or pitching staff as a whole) has that night.

How Often Do Strikeouts Occur?

High school baseball pitcher in red and white brings his knee up to his head before throwing the ball.

Strikeouts have always been a somewhat frequent part of baseball, but in recent decades, they have risen at a dizzying pace in professional baseball. On average, each MLB team averaged three more strikeouts a game in 2019 than they did in 1993, which is an increase of over 50% in barely a quarter-century.

In 2019, there were 42,823 strikeouts in Major League Baseball, an average of 8.81 per team, per game. That was a new MLB record, the 12th straight season with a new strikeout record. Strikeouts also have become the most common play in baseball, surpassing groundouts and hits in recent years.

Strikeout rates have exploded for many reasons. Namely, pitchers are throwing harder than ever, making the already-difficult task of hitting even tougher. As a result, modern analytics have shown that it is easier to score runs by bashing homers instead of stringing together multiple hits in one inning.

This in turn has led more players to emphasize hitting home runs, therefore employing more of an all-or-nothing approach where the goal isn’t to necessarily hit the ball as much as possible, but to hit it as high and far as possible – when and if you hit it.

So, with these factors at play, strikeouts have skyrocketed over the past two decades, with 2008 being the real jumping-off point. From 1998-07, MLB teams struck out anywhere from 30,644 to 32,404 times a season—a rather low variance for that large of a sample.

However, 2008 saw 32,884 strikeouts, a new record, and in the span of a dozen years, that number has bloated by nearly 10,000.

Consequently, with offensive approaches changing, strikeout totals have soared, as have home runs (4,185 in 2014 to 6,776 in 2019, a 61.9% jump in just five seasons), while the number of overall base hits have gone down, leading to three straight seasons (and counting) of the league having more strikeouts than hits, the only times in MLB history that has occurred.   

For many fans, executives, and other observers, the proliferation of strikeouts has been concerning, as they take more time than most plays (because they require a minimum of three pitches) and the ball is not hit into play at any point in time, so there’s less action.

At the rate things are going, though, that seems unlikely to change any time soon without drastic measures.

What Is an Immaculate Inning?

With pitchers striking out so many batters, they have been able to accomplish many high-strikeout feats. One of these is the “immaculate inning.”

So, what is an immaculate inning?

An immaculate inning is an inning where a pitcher strikes out three batters in one inning on nine total pitches, therefore striking out all three batters on just three pitches each. As of 2020, the feat has been accomplished 102 times by 94 pitchers.

Seven pitchers have two immaculate innings to their credit (with three of them still active as of this writing), while Hall of Famer Sandy Koufax is known to have done it three times.

That said, the number of immaculate innings may be inexact since reliable pitch data did not exist until the late 1980s, but there’s no denying they’ve become more common recently. 2017 and 2019 both saw a record eight immaculate innings, while 2014 had seven. Those three seasons alone encompass nearly a quarter of all immaculate innings.

Despite the proliferation of these innings, it’s still an impressive feat since it requires pitchers to be close to the strike zone, but also be able to fool hitters enough to avoid foul balls and balls being put in play.

What Is the Record for Most Strikeouts?

A view from the upper deck of the Phillies Stadium - Citizens Bank Park.

People may view strikeouts with a negative connotation in terms of the overall pace of the game, but high-strikeout performances are still celebrated and their records are well-known by many fans.

The most strikeouts in a career is 5,714 by Nolan Ryan, while the most strikeouts in a season (since 1901) is also held by Ryan, with 383 in 1973. The most strikeouts in a game is 20 in nine innings, done by four pitchers, while Tom Cheney struck out a record 21 men over 16 innings in 1962.

Nolan Ryan is perhaps the most well-known strikeout artist.

His career total is over 800 more than the next-highest total and he also led the league in punchouts 11 times, topping 300 strikeouts six times, both of which are records. Even more impressive, he did so in an era where batters struck out much less than today.

Likewise, the five instances of 20 strikeouts in nine innings are widely acclaimed as some of the most dominant pitching performances in history. Roger Clemens did it first in 1986, then again in 1996, with Kerry Wood (1998), Hall of Famer Randy Johnson (2001), and Max Scherzer (2016) all matching that effort in later years.

Lesser known is the effort of Tom Cheney, who on Sept. 12, 1962, pitched a staggering 16 innings (throwing an unfathomable 228 pitches), becoming the only MLB pitcher to date to strike out 21 batters in a game. However, his performance is not the official record because he only struck out 13 in the first nine innings of the contest.

Perhaps even more obscure is the tale of Ron Necciai, a minor league pitcher in 1952, who recorded the only 27-strikeout effort in baseball history, doing so in a low-level minor league game. In 2000, Brett Gray came the closest to that mark when he struck out 25 batters in a Frontier League contest.

Though strikeout totals have risen drastically, it is unlikely that many (if any) of these marks will be broken. For example, Cheney needed 228 pitches to record his 21 strikeouts and Clemens needed 151 in his second 20 strikeout game.

Ryan reportedly topped 200 pitches on multiple occasions and also pitched more seasons (27) than any player in history.

In today’s game, pitchers are rarely around for more than 110 pitches or so, with pitch counts approaching 140 being virtually unheard of these days.

For context, in the 1990s, there were 275 starts where a pitcher topped 140 pitches. In the 2000s, there were only 17 such starts. Since 2010, it has happened only twice: Edwin Jackson’s no-hitter in 2010 and Tim Lincecum’s 2013 no-hitter.

The point is, strikeout records are more likely to fall if pitchers have the opportunity to go deeper into games, therefore having more outs to get and more opportunities to punch out hitters.

Randy Johnson was the last pitcher to make a realistic run at Nolan Ryan’s modern single-season record of 383, finishing with 372 in 2001 and 364 in 1999. Since Johnson retired, only five pitchers have even topped 300, with Gerrit Cole reaching 326 in 2019.

For a career, Justin Verlander is the only active pitcher over 3,000 strikeouts, with 3,013 entering 2021, which ranks 18th all-time. However, Verlander will miss the 2021 season due to elbow surgery and won’t pitch until he’s 39 in 2022. Even then, he’s barely halfway to Nolan Ryan’s career mark.

No other active player is even halfway to Ryan. That perhaps is one of the greatest tales of irony in baseball: in an era where team and league strikeout records are falling by the wayside, the individual strikeout marks seem as ironclad as ever, if not more so. Regardless, they still will fascinate many fans for many years to come.

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Steven G.

My name is Steven and I love everything sports! I created this website to share my passion with all of you. Enjoy!

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