Overview
Koitsu refers to any play in which a fielder fails to catch or stop a ball and lets it get past them - a catcher missing a pitch, an infielder letting a grounder through, or an outfielder misplaying a fly ball or throw. Unlike the passed ball (hoitsu), an official statistic charged only to catchers, koitsu is an everyday descriptive term rather than a scoring category. When a koitsu occurs, the official scorer decides whether to charge an error, a passed ball, or a wild pitch, or to credit the batter with a hit depending on the difficulty of the play. If a catcher lets a third strike get past and the batter reaches first base, the pitcher is still credited with a strikeout while a passed ball or wild pitch is charged according to responsibility. The word appears constantly in Japanese broadcasts and game reports, so understanding how it maps onto the official scoring categories helps when reading NPB box scores and articles.
Koitsu, Passed Ball, Wild Pitch and Error Compared
The table below sorts out the terms most often confused with koitsu. The key distinction is that koitsu is an ordinary word describing what happened, while the other three are official scoring categories.
| Term | Japanese reading | Applies to | Treatment in the official record |
|---|---|---|---|
| Koitsu | kouitsu | Every fielding position | Not a scoring category. Depending on the situation one of the three below is charged instead |
| Passed ball | hoitsu | Catchers only | Charged when the catcher fails to hold a pitch that ordinary effort would have handled and a runner advances |
| Wild pitch | bouto | Pitchers only | Charged when the pitch is so far off target that the catcher could not have stopped it with ordinary effort |
| Error | shissaku | All fielders | Charged on a misplayed batted ball or throw that ordinary effort would have handled |
In other words, the very same event - "the catcher let the pitch get past him" - is scored as a passed ball if the catcher was at fault and a wild pitch if the pitcher was. When a fielder lets a batted ball or a throw get past, the question becomes whether an error is charged at all.
Does a Koitsu Always Mean an Error?
No. An error is charged only when the official scorer judges that ordinary fielding effort would have handled the play. An outfielder who lets a routine fly ball get past is charged with an error, but a fielder who cannot reach a screaming line drive or a ball that takes an unpredictable bounce may simply give up an extra-base hit instead. On a throw between fielders, whether the error goes to the thrower or the receiver depends on whether the throw itself was off line. Catchers are a special case again: their misplays are scored not as errors but under the dedicated categories of passed ball and wild pitch. If a catcher lets a third strike get past and the batter reaches first (the play Japanese fans call furinige), the pitcher is still credited with the strikeout while a passed ball or wild pitch is charged according to responsibility. In every case the final call rests with the official scorer, so two similar-looking plays can end up scored differently.
Frequently Asked Questions
Q. How is koitsu read and written in Japanese?
It is read kouitsu. The characters look much like those for hoitsu, the official statistic charged to catchers (passed ball), which is why the two are easily mixed up, but they are different words.
Q. What is the difference between koitsu and a passed ball?
A passed ball is an official statistic charged only to catchers, for failing to hold a pitch that ordinary effort would have handled. Koitsu is a general word for letting the ball get behind you, used at any position, and it is not a scoring category in itself.
Q. Is an error always charged on a koitsu?
Not always. An error is charged if the official scorer judges that ordinary effort would have handled the play; on a genuinely difficult ball the batter is credited with a hit instead. When a catcher mishandles a pitch, the play is scored as a passed ball or a wild pitch rather than an error.