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).
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