Overview
ERA is calculated as (Earned Runs × 9) / Innings Pitched. Since runs scored due to errors are excluded, it reflects individual pitching ability independent of defensive support. In NPB, an ERA in the 2.00s is considered elite, while sub-2.00 marks ace-level dominance. The all-time single-season record is Hideto Fujimoto's 0.73 in 1943, while modern standouts include Kazumi Saito's 1.75 in 2006 and Yudai Ono's 1.82 in 2020. The Sawamura Award criteria set 2.50 as the ERA benchmark. Only pitchers who reach the minimum innings pitched threshold qualify for the title, giving an advantage to durable starters. In recent years, advanced metrics like FIP (Fielding Independent Pitching) and xERA have gained traction, incorporating strikeout rates and batted-ball quality to provide a more comprehensive evaluation of pitching performance beyond traditional ERA.