防 御 率(ぼうぎょりつ)

ぼうぎょりつ

noun

ERA, earned run average

1. ERA, earned run average

A baseball statistic measuring the average number of earned runs a pitcher allows per nine innings pitched.

防御率(ぼうぎょりつ)が2.50だ。

The ERA is 2.50.

あの投手(とうしゅ)はリーグ最高(さいこう)の防御率(ぼうぎょりつ)を記録(きろく)した。

That pitcher recorded the best ERA in the league.

防御率(ぼうぎょりつ)が低(ひく)いほど投手(とうしゅ)の成績(せいせき)が良(よ)い。

The lower the ERA, the better the pitcher's performance.

防御率(ぼうぎょりつ) is a key statistic in Japanese baseball (野球(やきゅう)). It measures pitcher effectiveness.

Calculation

防御率(ぼうぎょりつ) = (自責点(じせきてん) × 9) ÷ 投球(とうきゅう)回数(かいすう)
自責点(じせきてん): earned runs
投球(とうきゅう)回数(かいすう): innings pitched

General benchmarks

2.00以下(いか): excellent
3.00前後(ぜんご): good
4.00以上(いじょう): below average

Related baseball terms

投手(とうしゅ): pitcher
先発(せんぱつ)投手(とうしゅ): starting pitcher
勝利(しょうり)数(すう): wins
奪三振数(だつさんしんすう): strikeouts

Baseball is extremely popular in Japan, with NPB (日本(にほん)プロ野球(やきゅう)) being the top professional league.

Related Words

Related: 投手(とうしゅ) (pitcher)

Related: 先発(せんぱつ)投手(とうしゅ) (starting pitcher)

general

Added 2026.1.29 8:59 · Revised 2026.9.2 13:01

08500/08871_bougyoritsu