SIERA (Skill-Interactive ERA)
An advanced ERA estimator that accounts for batted-ball type and the interaction of strikeouts, walks, and ground balls. Considered the most predictive of future performance.
Why "SIERA" Matters
Understanding siera helps you follow statcast situations during a baseball game. Pair this with our rules guide, positions overview, and the full baseball glossary.
Related Statcast Terms
- wOBA (Weighted On-Base Average)
A rate stat that credits each way of reaching base by its actual run value — a home run is worth more than a single, a w - wRC+ (Weighted Runs Created Plus)
Total offensive value adjusted for park and league, scaled so 100 equals league average. A wRC+ of 140 means 40% better - BABIP (Batting Average on Balls in Play)
Batting average on balls put in play, excluding home runs and strikeouts. League average sits near .300. Big swings abov - Barrel%
The percentage of batted balls hit with the ideal combination of exit velocity (98+ mph) and launch angle (roughly 26–30