What Does K Mean in Baseball Terminology?

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Baseball has a lot of rather unusual terms, which can be a tad confusing for those just learning the game. Take, for instance, the stand-alone letter K. What does K mean in baseball terms?

In baseball scorekeeping, the letter K represents an out by a strikeout. In a box in the scorebook, the score keeper will write the letter to denote when a batter is called out due to 3 strikes, whether he did that by swinging, or via an umpire’s call.

For the latter, when a batter strikes out “looking,” or without swinging at the 3rd strike, the score keeper writes the K backward in the scorebook. It’s just a quick way for scorebook reviewers to know how the batter struck out ~ and add yet another statistical column for strategists.

From Scorebooks to Everyday Baseball Vernacular

Baseball developed as a sport in the 1800s, and its significant growth was due in part to newspapers which carried reports of professional baseball contests to new audiences. This was aided in great part by the invention of the game’s scoring system, and the box score.

Sportswriter Henry Chadwick is credited with several innovations that proved very important to baseball’s early development. He developed the box score, which was the only way at the time to relay baseball action to the public who could not attend games.

This was before even photographs of games were available. When Chadwick introduced the box score and full-game statistics ~ plus some new statistics he invented and introduced, like batting average and earned run average ~ people could follow the play of their home teams and even individual players.

Almost everything that happened on the field during a game could be recorded, including every strikeout. However, writing the entire word “strikeout” into the little squares that populate a baseball scorebook is nearly impossible; and could become repetitive because a lot of strikeouts occur every baseball game.

Enter the Famous ‘K’

In response, Chadwick invented the K denotation. Why? You’ll find several responses to this, so we’ll list them in order of likeliness, with the first being the most likely explanation:

K is the most-prominent, or hardest-sounding, letter in the word “strikeout.” Early baseball scorebook abbreviations were limited to a letter per action, like R for scoring a run, or H for hit. However, S was already assigned to represent sacrifices (which occurred a LOT more than compared with today). Some even say that early on, S meant single, though that later was changed to 1B, as in 1-base hit. Anyway, most people say Chadwick chose the strange hard-sounding letter in the middle of the word (strikeout).
K is the last letter in the word “struck,” which was the word used most for the action back then, before strikeout became commonly used.
Writing the letter K requires using 3 strokes of a pen, and 3 is the number of strikes needed for a strikeout.

What’s Up With the Backward ‘K’?

Fans might notice a backward ‘K’ (ꓘ) either in a scorebook, posted on some high-tech stadium scoreboard, or on placards held up by people in the stands. A backward ‘K’ in baseball means a strikeout looking, or a K on a called third strike (as opposed to swinging and missing the 3rd strike).

Baseball Scoring System

In the simplest way, score could be kept in baseball by just counting the runs scored each inning ~ like you see on scoreboards at stadiums, with how many runs scored by each team in every inning, plus hits and errors, until the end of the game.

But early baseball pioneers were keen to understand that more would be needed. Additionally, it could be equally important to convey baseball games easily to a newspaper-reading public.

So baseball’s scoring system was invented, which usually involves a sheet or 2 filled with a list of names followed by little squares with diamonds inside. Baseball’s scorebooks allow scorekeepers to log everything for every batter, from pitched strikes and balls, whether a hit or out was recorded, and how so.

Numbers Assigned to Baseball Positions

Every position is assigned a number, from 1 for pitcher to 9 for the right-fielder, and in each little box on the scorebook the score keeper fills them in to record what just happened on the field ~ or outs, hits, runs, and substitutions.

Each action has a symbol or equation to represent it, as in K for strikeout, F9 for a flyball catch and out to right, or 6-3 meaning a putout by the shortstop throwing to the first baseman.

Scorekeepers can fill in the little diamond with a pencil or pen to indicate that a player ran all the way around the bases for a run. Scorekeepers also log substitutions, so statistics can be kept for every player.

Baseball Box Score

With the score-keeping system it wasn’t long before Chadwick proposed how to report game results soon after they were final. The box score is a miniature version of baseball’s scorebook, with a list of the names of all batters who played, and pitchers who pitched.

Only there’s not as much detail. A typical box score reported at bats, runs, hits and runs batted in for the batters; and innings pitched, strikeouts, runs, earned runs, and bases on balls for pitchers.

You can find the “K” used in the scorebook; not in box scores. As baseball grew and many teams played games in the same day, newspapers kept the box scores limited in how much information it could report ~ and even reduced them to what is called “agate type” in newspapers, or a font size at just 6 or 8 points. (A single point is about 1/72 of an inch, so being 6 or 8 points big means it’s quite small!).

Introducing the scoring system and box score were major developments for the rapid growth of baseball in general, and of Major League Baseball in particular. In no other sport is player and team statistics held so reverently, or studied so fastidiously.

Baseball’s early leaders could keep track of the results of games and player performances, keep standings, and use the numbers for a variety of things including personnel moves and player salaries.

Fans have been staring at the daily box scores in newspaper sports sections for well over a hundred years.

Other Uses of ‘K’ in Baseball

Over the years, the K in baseball has grown into usage away from scorebooks. Today you might see the letter used in a variety of ways:

On stadium scoreboards, to tout either a single strikeout, or list all strikeouts by a single pitcher with multiple K’s.

In newspaper headlines. Old newspapers crunched for space loved saving 8 letters of headline space by using K instead of strikeout.
Stadium crowd signs. In the 1980s and later, crowds at baseball games could hold up placards with big K’s on them, indicating how many strikeouts recorded by a particular pitcher. Usually this was planned in advance, for a game where a known strikeout pitcher would be starting. Several rows of fans could be seen holding up a dozen or more K placards when hurlers like Nolan Ryan, Kerry Wood, or Roger Clemens pitched.
Verbal jostling. Players might say the letter to mock another team, as in, “Here comes the K train!” when a good pitcher is entering the game. Or, players might purposely stutter to emphasize strikeouts to come: “It just k-k-k-k-keeps getting harder to hit!”

Final Words on What K Means in Baseball

Anyone new to the game of baseball eventually will come across someone saying “K” for something, or they will see it in print either on a scorecard or in newspaper print. Along with a whole bunch of acronyms and abbreviations for baseball, the newcomer will naturally want to know what it means.

In baseball, the letter K refers to a strikeout. It could be used in the recording of a strikeout for a pitcher, as well as a batter, as baseball keeps track of actions in detail to convey game play to readers and also to try to predict future performance on the field.

The acronym has spread beyond scorebooks and scorecards, and can be seen or heard in stadiums among the crowd, or even in everyday life. It’s among many baseball linguistic nuances that has expanded for public usage beyond the game.