Andrew Heaney Dons a Cowboy Hat

Last Friday, the Rangers signed Andrew Heaney to a two-year, $25 million contract. The oft-injured southpaw has called Los Angeles his home for the majority of his career, so how will the park switch affect his performance? Let’s consult the park factors.

This is nearly a clean sweep for Dodger Stadium, but it might not be as bad as it seems once diving into the specific factors.

First, we begin with the non-home run hit type factors. Here, Globe Life is less favorable for pitchers than Dodger is for all three hit type factors. Globe Life slightly inflated singles, while Dodger slightly suppressed them. Despite being a fly ball pitcher, Heaney has posted a better than league average BABIP just three times in his career, all of which occurred during the first four years of his career. He hasn’t posted a better than average mark since 2017, and that year it came in just 21.2 innings. The difference in singles park factors here shouldn’t have a significant impact, but Heaney could use all the BABIP help he could get.

Moving to doubles factors, the two parks suppress them, with Globe Life doing so a bit less than Dodger. On the other hand, there’s a significant gap in triples factors, but triples are so infrequent that it shouldn’t have an outsized effect. Overall, it’s clear that Globe Life is a worse BABIP park as per the hit type factors.

We now get to the home run park factors, which is the only one in which Globe Life is more favorable. The good news is it’s a pretty meaningful difference, as it suppressed home runs, while Dodger inflated them. This is a big deal for Heaney. Not only has he been a fly ball pitcher throughout his career, but he’s badly struggled to keep his fly balls in the yard. His career HR/FB sits at an inflated 16.1%, which is far above the league average during his time in the Majors.

In his career, he has actually posted a higher HR/FB rate than in away parks, which is quite a surprise. First of all, players generally perform better at home. Second, if I remember correctly, Angel Stadium, where he has called home for the majority of his career, used to be a home run suppressing park, at least when he was pitching half his games there. So I would have expected him to pitch better there. That said, moving to a new park that does indeed suppress home runs is a positive. An improved HR/FB rate would go a long way to closing the gap between his career ERA and SIERA.

The plate discipline metrics are interesting as the two parks are exactly neutral for strikeouts, but Globe Life, despite only marginally inflating walks, is significantly worse for pitcher walks than Dodger, which reduces them meaningfully. Heaney has never had any issues with his control and his home/away walk rate splits are almost exactly even. Given the small sample of innings he pitched at Dodger Stadium this season, this factor shouldn’t make a difference.

The batted ball type factors are next, and we find that Globe Life inflates line drives, while Dodger suppressed them, and slightly reduces pop-ups, while Dodger inflates them. Both these factors point to Globe Life being worse for BABIP than Dodger, and are likely already reflected in the less pitcher friendly hit type factors for the former. Heaney has typically posted worse than league average LD% marks, though not by a wide margin, while his IFFB% marks have been around average.

Finally, we get to the summary metrics in FIP and Basic. Looking at those, the parks are actually pretty close, with Globe Life slightly inflating FIP, but actually being neutral for run scoring, while Dodger was neutral in FIP, but suppressed run scoring.

Overall, I don’t think this park switch will have a significant impact on Heaney’s performance. However, given his struggles with the longball, I think moving to a park that has suppressed home runs is a bigger positive for him than some others. The bigger question is whether he could remain healthy and also whether he could maintain the velocity bump to a new career high he experienced this season. That velocity, paired with a new slider that generated an elite 24.1% SwStk%, resulted in a strikeout rate surge and breakout third of a season. Can he do it again?