"K" as in Cain

On June 13, 2012, San Francisco Giants pitcher Matt Cain completed the 22nd perfect game in baseball history. Adding to the excitement, it was the first ever thrown for the franchise, which joined the National League in New York in 1883. During the game, Giants fans celebrated each of Cain’s strikeouts by hanging a “K” sign just out of play on the ballpark’s brick right field wall.

In his 10-0 defeat of the Houston Astros, the right-hander recorded a career-best 14 strikeouts, tying the mark for the most in a perfect game, set by Sandy Koufax in 1965. When Cain and the Giants donated items from the brilliant performance to the Baseball Hall of Fame, the club included a “K” sign, measuring 22 inches by 28 inches.

The tradition of hanging signs on the walls of AT&T Park to keep count of a statistic began at the height of Barry Bonds’ career, well after fans at other ballparks established the popular tradition of displaying “K” signs for strikeouts. In 2004, San Francisco fans began adding a rubber chicken to a wire near the right field seats each time an opposing pitchers issued an intentional walk, to mock the visiting club’s tactics. A few years later, Giants fans switched to celebrating home team pitchers’ strikeouts by posting their own paper “K” signs.

The letter K has long represented a strikeout in the standard code for scoring baseball games, dating back to the game’s early history and the venerable Henry Chadwick. He was born in England and worked as a sportswriter covering cricket matches in the New York City area in the 1850s. Chadwick then forged an allegiance to the sport of baseball that lasted into the next century. He covered the games, published rule books and annual guides, created statistics such as batting average and ERA to rate the relative performance of players, and invented systems for scoring games to track every play. Chadwick often used either the first or last letter of key words in his scoring scheme. He used K to represent “struck out” because it is the last letter in “struck.” Like many of Chadwick’s innovations, this symbol is still used today.

Frank Pearsall took this portrait of Chadwick in 1874, it was one of many that the successful Brooklyn photographer took of the sportswriter over the decades. Chadwick used the images to illustrate his various publications and as gifts to friends and relatives.

Lenny Difranza is the assistant curator of new media at the National Baseball Hall of Fame and Museum