Skill-Interactive Earned Run Average (SIERA)
- 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.
3.50 ALL STAR
4.50 HIT THE BENCH
4.75 HIT THE SHOWERS
5.00 HIT THE ROAD