Adam Eaton Heads to Chicago’s South Side

Last Thursday, Adam Eaton officially signed a one-year contract with the White Sox to take over as their starting right fielder. The now 32-year-old is coming off a massively disappointing short season, as his wOBA dipped below .300. Will the park switch help fuel an offensive rebound? Let’s consult the park factors.

This is a very interesting park factor comparison, so let’s dive right in.

Eaton moves to Guaranteed Rate Field (GRF), a park that has suppressed batting average, and departing a park that has slightly inflated average. As I’ve mentioned in previous park factor comparison articles, these factors don’t describe what’s driving the batting average park factor, as it could be effects on BABIP, strikeout rate, or both. Eaton has been a strong BABIPer over his career, as he sports a .332 mark, thanks to a ground ball tilt and low IFFB%. He had posted six straight seasons of BABIP marks of at least .319 heading into 2020, before that mark came crashing down to just .260. That’s pretty shocking considering his LD% was above league average, while he never popped up. Eaton has also been quite consistent with his strikeout rate, always posting marks in the mid-to-high teens. A strong SwStk% generally hovering around 7% validates his contact ability. Since he relies on these two skills to generate offensive value, moving to a park that suppresses batting average is a real negative.

Moving on to the hit type factors, we find a mixed bag. GRF marginally reduces singles, while Nationals has increased them. This matches up with the AVG factors, as singles are the most common hit type. Since Eaton hits lots of singles, this is another factor that may affect him negatively. While Eaton isn’t a big doubles guy, he’s certainly not going to get any help from his new park, as GRF is a major suppressor of the hit type. At times, Eaton has been a strong triples hitter, hitting nine twice and peaking at 10 back in 2014. He hit seven in 2019 as well. But, he only hit one in 2020 and one in 2018, and at age 32, it’s fair to assume his triples-hitting ability is going to deteriorate. That said, this is a nice park factor jump in his new park, so perhaps it adds a triple or two to his total.

Lastly, the most important hit type park factor for fantasy owners is home runs. Eaton has never been a big home run hitter, as he’s topped out at just 15 and only hit double digits three times in his career. That’s of course a lot to do with his injury history, but also the fact his career HR/FB rate sits at just 8.5%. He’s generally posted marks in the high single digits to low double digits. The home run factor difference between these two parks isn’t massive, but it is meaningful. GRF is one of the best home run parks in baseball, while Nationals is slightly pitcher friendly for left-handers. Because Eaton has typically posted sub-30% fly ball rates, he won’t be able to take advantage of a more home run friendly park than a more fly ball heavy hitter. Clearly, the new park should help his home run output, all else being equal. But because of that low FB%, the effect isn’t going to be dramatic. A positive, but not as positive at it could have been if we were discussing a different hitter.

We now move along to SLG, which really just summarizes the individual hit type factors into one number. Even though GRF has the advantage in both triples and homers, it surprisingly slightly suppresses SLG, while Nationals has been neutral. This is likely due to the difference in doubles factors, which is significant, and the hit type is the second most common.

Finally, we get to wOBAcon (wOBA on contact) and RBIcon (RBI on contact, essentially an overall runs scored park factor, when the ball is put into play). Matching the lower SLG and the fact that its AVG factor is lower as well, it follows that GRF is a bit lower on wOBAcon. Oddly, the two parks are even and exactly neutral on RBIcon. I’m not sure I could come up with an explanation, but it does suggest the parks are pretty darn close in their effects on overall offense.

So what we learned here is that from a purely park factor perspective, this move could be a negative for Eaton’s batting average, but a positive for his home run total. The effects are unlikely to be significant, so I don’t think Eaton’s fantasy value should be adjusted. Perhaps a slightly lower average, but offset by an extra homer, and the runs scored and RBI that come along with it. Obviously, his value is highly tied to how much he’ll run and we can’t predict that outside of looking at his age and history, and perhaps new team’s philosophy on stealing bases, if that can even be discerned.