Using the Count to Measure Pitching Performance

An important aspect of pitching is the progression through the count of balls and strikes. Using data from the Pitch F/X database, we examine pitch-by-pitch data for twenty starting pitchers of elite and non-elite types. We see that the current count has a significant effect on the quality of the batting event. Elite pitchers are more likely to move from two-strike counts to strikeouts, and these pitchers are more likely to take advantage of eventual value of the plate appearance for particular counts. We examine how the pitch value of fastballs depends on the location of the pitch in the strike zone. A better understanding of count tendencies should lead to better measures of pitching performance.