A backward K in baseball means the batter struck out looking: the umpire called strike three and the batter never swung. A regular K means a swinging strikeout. Scorekeepers flip the letter so anyone reading the scorecard can tell the two apart at a glance. The chart below shows the backward K alongside every common scorekeeping symbol.
Baseball scorekeeping symbols
The backward K and every symbol on a scorecard
Numbers refer to fielding positions: 1 pitcher, 2 catcher, 3 first base, 4 second, 5 third, 6 shortstop, 7 left, 8 center, 9 right.
Strikeouts
K
Backward KStrikeout looking: called third strike, batter did not swing.
K
Strikeout swingingBatter swung and missed at strike three.
Hits and reaching base
1B
SingleBatter reaches first on a hit.
2B
DoubleBatter reaches second on a hit.
3B
TripleBatter reaches third on a hit.
HR
Home runBatter circles the bases.
IBB
Intentional walkDefense chooses to walk the batter.
HBP
Hit by pitchBatter is awarded first after being hit.
E6
ErrorBatter reaches on a misplay; the number is the fielder who erred.
FC
Fielder’s choiceBatter reaches while the defense gets a runner out elsewhere.
Outs in the field
6 to 3
GroundoutShortstop fields it and throws to first.
F8
FlyoutCaught fly ball; here by the center fielder.
L4
LineoutCaught line drive; here by the second baseman.
P5
PopoutCaught pop up; here by the third baseman.
3U
UnassistedFirst baseman makes the out alone.
DP
Double playTwo outs on one play.
TP
Triple playThree outs on one play.
Other plays
SAC
Sacrifice buntBatter bunts to advance a runner and is out.
SF
Sacrifice flyFly out that scores a runner from third.
SB
Stolen baseRunner steals a base.
CS
Caught stealingRunner thrown out trying to steal.
WP
Wild pitchRunner advances on a pitch the catcher could not handle.
PB
Passed ballRunner advances on a catchable pitch the catcher missed.
Scorekeeping styles vary from scorer to scorer; the symbols above are the most widely used.
Why a Backward K Matters
Striking out looking is often seen as worse than going down swinging, since the batter took a pitch in the strike zone without trying to protect the plate with two strikes. Coaches track backward Ks to spot hitters who are too passive, while pitchers with lots of called third strikes usually have excellent command and a pitch that freezes hitters. In the box score, both kinds count simply as a strikeout.
Where the K Comes From
The K dates to the 1860s and Henry Chadwick, a sportswriter who created much of baseball’s early scoring system. He used K, the last letter of “struck,” because S was already taken by other plays like sacrifices. The backward K came later as a scorer’s convention for strikeouts looking.
Related
What is a whiff · Force out vs. tag out · Baseball positions and numbers
Official scoring rules are in the MLB.com glossary, and the National Baseball Hall of Fame covers Henry Chadwick and the history of scorekeeping.
