Sabermetric Series, Part 4: ERA Estimators
Welcome to Part 4 of this Sabermetric Series, where we will be moving from hitters to pitchers. We're going to start with the basics and look into the benefits of using various ERA estimators. We'll go over a whole bunch of fun acronyms, such as:LOB%
K-BB%
FIP
xFIP
SIERA
ERA-/FIP-/xFIP-OK, so why all these random letters? What's wrong with good ol' ERA (acknowledging that they, too, are just letters)? Well, ERA lets us know a pitcher's past results, but it doesn't tell us if those results are…