Author Archive

Jakob Junis and the Disappearing Fastball

© Isaiah J. Downing-USA TODAY Sports

This is Kyle’s first piece as a FanGraphs contributor. Kyle is a lifelong baseball fan who has always been enamored with the numbers and analytics behind the game. He has written for PitcherList on the pitcher GIFs team and for his own personal blog, covering topics from player analysis to the draft, mostly focused on the Angels. Kyle is a senior at the University of California, living in the Bay Area and studying education and math. As an aspiring teacher, he wants to think and write about the game of baseball from the perspective of an educator.

From 2017-20, Jakob Junis was a below-average starter for the Royals, posting a 4.78 ERA and 4.77 FIP. After a poor 2021 that saw him pitch out of the bullpen, he was non-tendered by Kansas City and signed with the Giants. Fresh off a 107-win season that was bolstered by career resurgences from hurlers like Johnny Cueto, Anthony DeSclafani, and Alex Wood, San Francisco clearly saw a path to improvement for Junis. Mostly serving as a member of the starting rotation, Junis has done just that – his FIP has improved by about a full run (3.83). While he hasn’t thrown harder, landed more strikes, or added movement to his pitches (his sweeping slider has actually lost about an inch of break), he’s made one important change, and it’s one that is emblematic of pitching philosophy in the modern age.

Jakob Junis Pitch Usage
Year(s) Fastball/Sinker Slider Changeup Other
2017-20 52.6% 39.9% 5.9% 1.7%
2022 32.5% 51.8% 15.7% 0%

Read the rest of this entry »