Most- and Least- Potent Pitch Combos

Given this site’s belief that pitches aren’t thrown in a vacuum, and the effectiveness of one pitch is affected by the pitches that preceded it; I wanted to identify the most- and least-potent 1-2 pitch combinations in the 2018 Major League Baseball season. To accomplish this, I built a Pitch Combo Effectiveness Tool based on all 2018 pitches thrown in Major League Baseball.

The approach I took was to evaluate every pitch as the second pitch in a 1-2 combo (forcing us to exclude at-bat first pitches). I defined these pitch combos using the pitcher, the pitch types of both the 1st and 2nd pitches (e.g. ‘Four-Seam Fastball followed by a Curveball’), and the pitch location change from the 1st to the 2nd pitch (e.g. ‘The 2nd pitch was further down and more inside than the first pitch’). I then gauged the effectiveness or value of these pitch combinations using the sum of the wOBA Added for both the 1st and 2nd pitches. Lastly, to ensure we were only looking at common pitch combos, we filtered the results to pitch combos observed at least 10 times in 2018.

The chart showing every pitch combo is below:

So how can we use this Pitch Combo Effectiveness Tool and what can we learn? The depth of detail is great and patterns are surprisingly strong and insightful. For each pitch combo, we also report average pitch speed change and difference in breaking action between the 1st and 2nd pitches. We also measure the Usage Rateof that combo for the pitcher.

The results show clear patterns and trends in what is most and least effective for individual pitchers. As an example, we’ve captured the Max Scherzer results below. Scherzer throws a LOT of Four-Seam Fastball, Four-Seam Fastball combinations, but they are FAR more effective when the 2nd pitch is more inside to the hitter and/or further up in the zone. Almost all of his negative wOBA Added pitches (good for the pitcher) follow this location movement trend. Pitches that defy that trend are almost all further outside and/or lower in the zone.

Visit the Pitch Combo Effectiveness Tool permanent page, or do your own investigation and exploration in the embedded version below.