Surprise! Park Switch Boosts Stephen Piscotty’s Value

Last week, the Athletics traded for Stephen Piscotty, alleviating a bit of the great depth in the Cardinals outfield. Piscotty is coming off a forgettable offensive performance, in which he dealt with injuries, a minor league demotion, and the terrible news that his mother was diagnosed with ALS. Typically, the knee-jerk reaction is a move to Oakland will likely hamper a hitter’s offensive results. But surprisingly, this appears to be one of those rare instances in which the park switch may actually provide a boost. Let’s dive in.

Woah, that’s a far friendly hitting environment in Oakland compared to St. Louis than I would have guessed. We see from the first column, run scoring, that Oakland was actually a tick better than neutral in 2017, while Busch drastically suppressed runs scored. That’s all well and good, but we’re more interested in finding out what’s driving the discrepancy and how that may affect Piscotty.

First, we dive into the hit types. Busch’s only advantage in in singles, which likely means it offers slightly better BABIP potential, but likely not by a significant degree. The better doubles and triples rates in Oakland (wowzers that triples factor is insane!) are probably not enough to make up for the much more frequent single.

We then move on to homers, the factor we probably care most about. Both suppress the long ball, which is something we all basically knew, but Busch did so more dramatically than Oakland this season. So while Piscotty will continue to be held back by his home park, it might not be to as great a degree. And guess what…Piscotty has underperformed his xHR/FB rates for three seasons running now. He actually owns a better HR/FB rate in away parks than at home, sitting at just 11% at Busch, but 13.9% in away parks. Just more proof that his home run power has been hampered.

Piscotty’s Brls/BBE and resulting xHR/FB rates have tumbled each season, but he’s still just entering his age 27 season and deserves a mulligan for all he dealt with this year. So I think he has real home run upside.

In terms of batted ball types, the most interesting to note is the line drive rate, in which Oakland inflate, while Busch deflates. That may be enough to offset the loss of singles from park factor and keep his BABIP in a similar range as if he hadn’t been traded. And he could certainly use the line drives and BABIP rebound, as both plummeted this season.

The strikeout and walk rates are close enough that we could just focus on his skills when forecasting his 2018 performance. He swung at significantly fewer pitches both inside and outside the zone this season, which led to a walk rate surge, and also managed to cut his SwStk%, though his strikeout rate didn’t budge because of the aforementioned fewer swings inside the zone. His Swing% actually remained just above the league average, which seemingly doesn’t match with a 13% walk rate. I’d bet on some serious regression there, but he should maintain some of that growth, giving up more than he keeps.

Overall, this is probably a good move for his value as the park switch is a positive and his playing time is likely to be more secure in a less crowded outfield. I’m definitely buying low here.