I thought this was kind of interesting:

Hi Mike,
Why do they use the K for scoring a strike out?

Barbara Farrell

Hi Barbara,
The following is an excerpt from Paul Dickson's The Joy of Keeping Score:
K IS FOR K AS IN STRIKEOUT

Once again, he winds up and goes for the K.

-Traditional line of sportscaster describing a pitcher racking up strikeouts

K. It is the most abiding of abbreviations, taken, by all accounts, from the back rather than the front of the word "strike."

It was the invention of Henry Chadwick, notwithstanding an article in The Sporting News of June 12, 1965, asserting that the first person to use the K was M. J. Kelly, a baseball writer for the New York Herald and editor of the DeWitt Guide for 1868. True, Kelly used it, but he had learned it from Chadwick, who, among other things, became the Herald's first baseball editor in 1864, and who used the K symbol in 1868 in Beadle's Guide, of which he was the editor. From time to time, it has been further asserted that the K was Kelly's appropriation of his own initial, but this is unsubstantiated speculation-similar to the occasionally mentioned notion that K is the letter that most resembles a batter standing at the plate.

On a number of occasions Chadwick told how the scoring system was created in the early 1860s. One of the most complete renditions appeared in 1883 in Peck and Snyder's Scorebook, which was created by Chadwick. "Over twenty years ago we prepared a system of short-hand for the movements of contestants in a baseball match, which system is now familiar to every scorer in the country. The abbreviations of this system were prepared on the mnemonics plan of connecting the abbreviated words in some way or another with the movement to be described..."

So it was that Chadwick was able to explain: "K stands for 'struck out' as it was the prominent letter of the word strike, as far as remembering the word was concerned." At another point in the discussion of his system, Chadwick notes that "the letter K in struck is easier to re member in connection with the word, than S."

Most of Chadwick's ideas have long ago been dropped, including the use of L for fouL, which is totally consistent with the use of K. Incidentally, Chadwick's system was unlike any that have come into use in the twentieth century. For one thing, it used letters, not numbers, for defensive plays: for instance, C for a putout at third and RO for a putout between bases. There were six error symbols, including • (bullet) for a muffed ball and 0 for a dropped fly ball.

Take care,
Mike

For those of you who don't know, Henry Chadwick was Bill James, just a hundred years earlier. However, whereas James at least had baseball guides and encyclopedias on which to base and test his theories, Chadwick had nothing to start with. Batting averages were expressed in runs per game with a remainder and "hands lost" (i.e., outs) per game (also with a remainder). It may have been the germ of an idea for Runs Created, but it was like using Roman numerals to do long division (and we all know how painful that can be). Chadwick was the man who started it all, from scoring games to keeping real stats to disseminating them in a baseball annual (the great Beadle's Dime Base Ball Player).