Using xK and xBB With SIERA
Expected ERA metrics like SIERA, FIP and xFIP are one of the best sabermetric developments we have benefited from in recent years. No longer do we have to eye the various luck rates and attempt to make mental calculations as to how lucky or unlucky a pitcher has been. Expected ERA metrics do the work for you and spit out a number on the same scale as ERA so you could quickly identify those pitchers benefiting from good fortune and those who have not.

