Nathan Eovaldi’s Bowl To Be Filled With Cowboy Soup Now, Instead of Clam Chowder

Last Tuesday, the Rangers signed Nathan Eovaldi to a two-year, $34 million contract. While I love New England Clam Chowder and assume Eovaldi enjoyed many bowls of the delicious soup during his four and a half seasons with the Red Sox, he might now be salivating at the prospect of filling his belly with Texas Cowboy soup, which sounds just delightful. Entering his age 33 season, how might the change in home venue affect his results? Let’s consult the park factors to find out.

It’s nearly a clean sweep for Eovaldi’s new home, with the only wins by Fenway by the smallest of margins. So the kneejerk reaction looks like this is a win for Eovaldi. Let’s dive into the individual factors to be sure.

Both parks increased single frequency, but Globe Life did so just a bit less than Fenway in 2022. Since singles occur most among all hit types, it has the biggest impact on BABIP. That’s something Eovaldi has struggled with at times during his career. His career mark stands at .310, which is well above the league average, and he had posted marks above .300 for three straight seasons until this year’s .298, which finished barely below. Since 2019, he has posted a .321 BABIP at home, versus a .314 mark in away parks. So clearly it wasn’t just his home park causing an inflated BABIP, but he did post a higher mark at home, which matches with the factors.

The move wouldn’t seem to do a whole lot for his singles allowed. But it might for the other hit types. Globe Life slightly suppressed doubles, while Fenway was actually the best park to hit doubles in last year. So the move should certainly decrease his rate of doubles allowed, which will both be good for his BABIP and ISO allowed, and reduce his ERA, all else being equal.

Finally, we move to triples, the least frequent hit type. The gap here is also large, but a bit smaller than for doubles. Eovaldi only allowed two triples at home since 2019, versus four in away parks, which is more a result of tiny sample size for an infrequent event than any mismatch with the park factors.

Next is home runs and here we learn that the parks sport the exact same factors, both suppressing them. Eovaldi has actually allowed a significantly lower HR/FB rate at Fenway than in away parks. He has also had a bizarre career of HR/FB rates. During his first five seasons, he posted single digit marks never exceeding 8.1%. Then he posted double digit marks, over his next four seasons, including 18.7% and two over 20%, all of which came over partial seasons. His double digit streak broke in 2021 with an 8.2% mark, but he was at it again, suffering from gopheritis this year as his HR/FB rate jumped back up to 17.2%. It’s anyone’s guess where his HR/FB rate will land in 2023, but at least we know his new home park shouldn’t impact our projection much. Unless of course he pitched to his home park, which might explain the big discrepancy between his home and away HR/FB rates while with the Red Sox.

Moving onto strikeout and walk factors, we see minor differences here that shouldn’t have much, if any, impact on his projections. He has actually posted a much higher strikeout rate and much lower walk rate in away parks than Fenway, which is quite surprising.

Normally we would discuss batted ball type factors, but the ones that should affect performance in LD and IFFB, are identical. Like some of his other metrics, his LD% and IFFB% marks have been up and down throughout his career, so it’s hard to know what you’ll be getting from him.

We now shuffle over to the summary metrics in FIP and Basic. It’s always strange to see such difference in these two metrics and here’s another example. While Globe Life slightly inflates FIP and Fenway was neutral, Globe Life is neutral for overall run scoring, while Fenway is a significant hitter’s park. This is likely due to Fenway’s BABIP-inflating powers, as FIP only factors in strikeouts, walks, and home runs. When accounting for BABIP, we more accurately determine that Globe Life is a much better environment for pitchers than Fenway.

So overall, this is a clear upgrade for Eovaldi, all coming in the form of BABIP. It’s something he has struggled with throughout his career, which makes him a good candidate to really benefit from this park switch. I am concerned about his loss of fastball velocity, so keep in mind that just because the park switch is a good thing, it doesn’t mean his forecast will automatically be better than how he performed in 2022. Instead, I usually create a forecast as if he was staying in his same park, and then make the park adjustments.