Why Does ‘K’ Mean Strikeout in Baseball?


Written by

Michael Rogers



Leo Hagenes

why does 'k' mean strikeout in baseball

In baseball scoring, H stands for Hit, HR for Home Run, AB for At Bats, HBP for Hit by Pitch, and the list goes on. With that logic, S should be Strikeout. Well, not really; the strikeout symbol is actually the letter K.

You can notice many of the “K” and “K backward” on the outfield fence during MLB games hung by the fan to keep track of the feat.

Why does ‘K’ mean strikeout in baseball, and how it’s often used? Read on to learn many interesting facts.

Why are Strikes Called K?


Let’s start with strikeout meaning in case you are new to baseball. A pitcher achieves this feat, meaning they have thrown three swinging or looking strikes to the batter.

There are some exceptions if the catcher makes mistakes, but in most cases, a strikeout would mean the batter is out.

Now, as for the reason K in baseball means strikeout, that is because the letter “S” was used to denote scoring a sacrifice already. So, Henry Chadwick, a sports reporter, instead used “K,” the last letter of “struck,” to refer to a strikeout in the baseball scorebook.

The K was used in the first box score ever made in baseball by Henry Chadwick, along with many other abbreviations that stand for the feat achieved by players. He created this box score to record an 1859 baseball game. And the rest is history.

Also, you can sometimes notice “SO” as another abbreviation for a strikeout.

Backwards K in Baseball


As mentioned above, strikeout, or K, denotes three strikes, resulting in the batter’s out. Yet, besides the standard K in baseball MLB, there is also the backward “K” appearing often in baseball games.

For your information, this backyard letter refers to the feat where the batter struck out at the third strike without swinging.

Strikeout K Signs

As K stands for strikeout, fans of baseball teams often bring signs with this letter to a game. They would raise the sign when their pitcher successfully strikeouts batters from the opposing team.

This goes the same for K backward signs. In fact, many fans even keep track of the number of strikeouts by putting these signs in a row. It’s a form of celebration and also a provocation. Indeed, competitiveness is what makes sports exciting.


The reason why does ‘K’ mean strikeout in baseball is simple and pretty funny: the S was already taken, so they use the letter K instead.

Now, if you join a fiery and exciting baseball game, noticing the K signs put up by fans of both teams no longer confuse you. They are cheering their pitcher’s strikeout credit!

Rate this post
From the blog

You may also like