Eric Jagers is on the fast track in the pitching world. Little more than seven years after discovering Driveline during his freshman year of college, the 25-year-old Iowa native is now the assistant pitching coach for the Reds. Promoted to the position last month — he replaced Caleb Cotham, who is now the Phillies’ new pitching coach— Jagers spent last season as the club’s assistant pitching coordinator. Previously Driveline’s Manager of Technical Development, he remains with the Seattle-area training facility in an advisory role.
Jagers touched on a handful of pitching-related topics, and a pair of Cincinnati hurlers, earlier this week.
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David Laurila: What do many people not really understand about the technological aspects of pitching development?
Eric Jagers: “That’s a good question. With all the pitch-tracking technology — and there are a lot of people who do understand this — it’s all the pieces together, as opposed to the segmented ways we tend to look at things: a pitch has got this movement, and it’s also got this location. But really, those things morph together. The location piece adds to the movement piece. A fastball with a lot of hop that’s also up in the zone is maximized. Same with a sinker that’s at the bottom of the zone. Conversely, with a sinker at the top — when we’re looking at short-form movement — it’s easy for the data to fool you into thinking it’s something it’s not.
“I think a lot of people are pretty comfortable viewing movement on TrackMan, Rapsodo, and now Hawk-Eye. But those are just giving us a piece of the equation. We need to factor in all the variables.”
Laurila: Can you elaborate on what you mean by data fooling you into thinking it’s something it’s not?
Jagers: “It’s easy to come up with an answer, and the easiest person to fool is yourself. It’s like the Richard Feynman quote. Basically, it makes it really easy for us to tell us the story that we want to tell, and we don’t have a full understanding — at least on surface-level stats — of what a complete pitch is. Going back to location and movement, in order to get a true vertical-break number, it’s not just 18 inches of spin-induced vertical movement. It’s that, plus where it was released from, plus where it entered the zone. All of those things together equate to one true number. Read the rest of this entry »