Projected ERAs of D-back Starters in 2021

Luke Weaver, starting pitcher. Photo by Norm Hall/Getty Images Next season, how will the Diamondback starting pitchers perform? To answer that question, let’s create an equation (you could call it a model).

First, I give credit to a previous work, especially for BABIP and LOB weights, that is shown in a model created in 2015 by Matt Jackson.

Let’s start with assumptions.

A pitcher’s results are a combination of his skill (which is repeatable) and factors he cannot control.

FIP is a measure of a pitcher’s skill. Although far from perfect, in general it can predict how well a pitcher will pitch in the future.

Factors that a pitcher cannot control include BABIP, runners left on base (LOB%), and…