Consistency metrics provided by @UmpScorecards represent the proportion of taken pitches considered consistent with the umpire’s established zone in any given game.
Our algorithm begins by finding the ‘established’ zone, or what we call the Estimated Umpire Zone (EUZ). In short, the EUZ represents the boundary across which the umpire should change his mind between a strike and ball call, based on his calls in a particular game; pitches inside the EUZ have a greater than 50% chance of being called a strike, and pitches outside the EUZ have less than a 50% chance of being called a strike. This process was inspired by the work of Dr. David Hunter, professor of mathematics at Westmont College. To read more about our specific formulation and implementation of the EUZ, click here.
From there, we consider a taken pitch’s call to be consistent if one of two conditions hold: the pitch fell within the EUZ, and was called a strike; the pitch fell outside the EUZ, and was called a ball. Here, we simply use the reported location of the pitch, as opposed to a Monte Carlo simulation.