Someone started keeping score at our weekly pickup baseball games in Brooklyn, which seemed sweet when I realized it meant we could start keeping our stats, and then significantly less sweet when I noticed I profile similarly to Luis Castillo (after two games, I’m slashing .285/.375/.285).
Anyway, on the bench Sunday we got to wondering why a strikeout is scored a “K.” I figured it wasn’t “S” because of sacrifices, but we couldn’t determine why it would be “K” instead of “T” or some other letter in the word “strikeout.”
The use of “K” for a strikeout was invented by Henry Chadwick, a newspaper journalist who is widely credited as the originator of the box score and the baseball scorecard. Both the box score and scorecard persist largely unchanged to this day, as the game itself is largely unchanged except for the number of balls and strikes allowed to the pitcher and batter. The letter “S” was used to coin “sacrifice” so Chadwick decided to use “K”, with “K” being the last letter in “struck.” Chadwick also invented many other baseball scoring abbreviations, such as using numbers to designate player positions (progressing from the batter, pitcher [1] and catcher [2], through the infield, with the shortstop counted after the basemen, at number 6, to the right fielder [9]).[2]
That Chadwick first established the convention of using the “K” abbreviation is well-founded, with reliable and authentic primary materials surviving (see citation above). Those unaware of Chadwick’s contributions have speculated that “K” was derived from the 19th century pitcher Matt Kilroy‘s last name. If not for the evidence supporting Chadwick’s earlier use of “K”, this speculation would be reasonable: Kilroy did much to raise the prominence of the strikeout, setting an all-time record of 513 strikeouts in 1886, only two years after overhand pitching was permitted. Kilroy’s record, however, is forever confined to its era: the pitcher’s mound during his record-setting season was only 50 feet (15 m) from the batter; it was moved to its current distance of 60’6″ in 1893. The modern record (1901-) is 383 strikeouts, held by Nolan Ryan, one better than Sandy Koufax’s 382.
That makes sense, I suppose. “K” somehow does seem more appropriate than “T” or “I” or whatever, but probably only because I’m used to it. Plus those letters can’t be written backwards to denote called third strikes.
But I like the Kilroy story better, for Styx-related reasons.
Tedquarters 
Great post, Luis.
It’s odd (cool) to me that things like this have persisted for 100+ years, especially the distance from to the mound. The game has changed so much but they ‘got it right’ way back in 1893. This, especially considering how hockey rinks have gotten bigger, the 3-point line has swelled, etc.
Side note on the K… Back in my single days, I would ask “what does a backwards K mean?” to a girl early on in the relationship. My current wife (and babies’ mama) was the first and only one to get it right. That wasn’t the clincher, but it sure did help her cause.