True Earned Run Average, like FIP, attempts to quantify a pitcher's performance based on what he can control. But unlike FIP -- which factors only home runs, strikeouts, walks and HBPs -- tERA also accounts for batted-ball tendencies. That means pitchers who record mostly ground balls and popups, as opposed to line drives and fly balls, are rewarded for inducing weaker contact.
For example, if a pitcher has a high FIP but has also gotten a lot of weak contact on balls put in play, his tERA will be lower than his FIP.
Watch: Carlos Carrasco's barrage of strikeouts and ground balls contributes to a low tERA.
Why it's useful
ERA places a value on a pitcher's performance, but it doesn't factor misfortune into the equation (the timing of hits, poor defensive positioning, etc.). FIP, while focusing on strikeouts, walks, hit by pitches and home runs, ignores the fact that a pitcher does indeed have some influence on balls in play. tERA accounts for that element.
tERA is meant to be a more accurate indicator of a pitcher's performance than ERA. Even though most fantasy leagues count ERA, tERA can help assess a pitcher's talent and predict future success.