The Colorado Rockies located the fastball low in the zone better than any other MLB team in 2021
In 2021, Colorado Rockies pitchers located 3,545 four-seam fastballs in the lower 3rd of the zone. The next highest mark came from the Arizona Diamondbacks staff at 3,063.
The Rockies, unlike the rest of MLB, are not on the train of drafting and developing pitchers with an ideal modern fastball — a heater with high levels of active spin that creates above-average vertical break to play up in the zone.
Colorado’s arms consistently have lower spin rates (thus less spin-based movement) which leaves their vertical break measures below the league average. Vertical break describes a pitch’s movement upward or downward in the zone. Fastballs remain pretty flat and more spin-based movement on a four-seam fastball will result in even less drop.
For example, Germán Márquez and Austin Gomber both had four-seam fastball spin rates that were in the bottom 31 of the league (among more than 260 qualifiers) and both of them pitched very well at Coors Field.
Vertical break, along with a pitcher’s armslot/release height, and extension to the plate, combine to create a pitcher’s vertical approach angle (VAA).
VAA is the angle at which a pitch crosses home plate. For example, if a pitcher has a lower three-quarters arm slot and gets a lot of vertical break on their fastball, it will have a “flatter” approach angle. This “flatter” pitch will appear to rise on a hitter due to its increased resistance to gravity.