PitchFX Data on Arrieta’s Last Spring Training Start Shows His Release Point Was Wild

Jake Arrieta’s inconsistent release point in 2016 was akin to the invicibility star in Mario Kart, where wild driving is beneficial, not deadly. Though Arrieta finished the season with a 3.10 ERA, 3.52 FIP, and two shut-down World Series starts, his vertical release point was 29% more inconsistent than in his Cy Young season.

The degree of release point inconsistency even predicted Jake’s slider movement. His release point variability, then, makes for an appropriate marker when trying to find evidence that Arrieta is recapturing the magic of 2015.

It’s never too early to track release points, even in March. Luckily, we can do this because PitchFX sensors were set up for Arrieta’s last start against the D-backs on March 23. Let’s just say Spring Training is more necessary than I originally thought.

Below is Arrieta’s vertical release point graph. The dots and bars on the left are all games from 2016, while those on the right are from his most recent start. Pay close attention to the width of the bars, as wider bars mean more release-point inconsistency. Pitchers want these bars as small as possible because that means they are repeating their mechanics.

You don’t even need to squint to see the dramatic difference in release point variability during Arrieta’s last start. For example, his slider release point inconsistency appears to be at least five times greater than years past. It is apparent that he was either working out the kinks or trying something new.

Of course, Arrieta’s release point in March probably doesn’t predict anything come summer. I bring this up because some players *cough* Ryan Braun *cough* have complained about the length of Spring Training. But while hitters can perhaps dial in their timing more quickly, maybe an entire month of practice games truly is necessary for some pitchers before embarking on another grueling 162-game stretch.