Why is VAA important and important for the Colorado Rockies?
Vertical approach angle (VAA) is a huge determinant in how pitchers will be successful given the location of their pitch when looking at the vertical plane (up in the zone vs. down in the zone). It’s become clear that pitches with a higher/flatter VAA (greater than -4.5°) work better up in the zone and pitches with a lower/steeper VAA (less than -4.5°) work better lower in the zone.
Work from the University of Iowa’s baseball student managers quantifies this information and also presents some handy graphs and charts.
Unfortunately, VAA is not a publicly available statistic. However, induced vertical break is available along with arm slot/release height and extension data. As a result, we can’t look at exact VAA measures but we can get a rough estimate of a pitcher’s fastball VAA.
Looking at Rockies’ pitchers, they, again, do not generate high levels of vertical break on their fastball.
The Rockies also have a lot of traditional 3/4 or straight-up arm slots with Marquez, Freeland, Gomber, Senzatela, and Estevez (five of their most highly used pitchers) releasing the ball at or above MLB’s average release height of 5.8 feet.
Jon Gray and Daniel Bard were outliers to this measure, both releasing the ball several inches lower than the average MLB pitcher. Still, neither Gray nor Bard generated lots of vertical break last season to create a higher/flatter VAA.
With these lower/steeper VAAs on the Rockies’ staff, they’re able to more effectively target the bottom of the zone and create Coors-necessary ground balls.