• One of the most accurate metrics we can use to assess a pitcher’s underlying skill level.
  • Like FIP & xFIP: It is an ERA estimator that attempts to go deeper than traditional stats
  • Unlike FIP & xFIP: It does not ignore balls in play
    • Thus, SIERA best models what makes a pitcher successful
    • NOTE: tERA & SIERA are somewhat redundant; most statisticians prefer the more modern of the two (SIERA)
• Do not get lost in the complexity of the equation, instead notice the color-coded variables:
  • K/PA: High strikeout pitchers keep batters off the bases and generate weaker contact
  • BB/PA: Handing out free bases has to be limited
  • GB-FB-PU: Weak contact limits base hits and earned runs (batted ball stats are observed and prone to human error).

NOTE: It is often best to use FIP, xFIP and SIERA in conjunction to properly contextualize a pitcher’s ERA.