Joining New Teams — Ross & Nova & Roark, Oh My

The news just keeps coming, as players are signing a flurry of deals, making it hard for me to keep track of all the moves and those expected to become official. Within just the last couple of days, a trio of mediocre starting pitchers have joined new teams either via free agency or trade. Rather than go through the full park comparisons like I have been all week, let’s summarize the potential effects on Tyson Ross, Ivan Nova, and Tanner Roark. Will the park and team switches make these pitchers any more appealing? Let’s find out.

Tyson Ross Signs With Tigers

Despite missing most of the 2016 and 2017 seasons recovering from surgery to relieve thoracic outlet syndrome, Ross enjoyed a respectable season this year split between the Padres and Cardinals. Perhaps another season remove will lead to a velocity rebound and increased effectiveness of his once-lethal slider.

The vast majority of his career and most of his 2018 season was spent with the Padres, so we’ll compare Petco Park to Comerica Park. Amazingly, though probably not surprisingly, Petco suppresses every single hit type, while Comerica inflates every hit type except doubles, in which it slightly reduces them. The move to a more hitter friendly venue for every hit is bad news for Ross. The only factor significantly less favorable is triples, which aren’t hit often and so shouldn’t affect Ross’ results too dramatically.

Even for strikeouts, Petco slightly boosts them, while Comerica reduces them. After posting a strikeout rate in the mid-20% range from 2013-2015, he posted a sub-20% mark this season. And this was playing in the National League, where starters posted a strikeout rate 0.6% higher than AL starters. The only factor Comerica is more favorable for pitchers in is IFFB, or pop-ups. Ross hasn’t been much of a pop-up inducer, so this could provide a small benefit.

Overall, between the park switch and the move to the American League, this kills Ross’ value and I wouldn’t even recommend him as a cheap AL-Only guy either.

Ivan Nova Traded to White Sox

So much for that National League strikeout rate boost. Nova has posted identical 16.7% strikeout rates in his two full seasons with the Pirates, which is actually below his current career mark. The move back to the American League will do him no favors.

I’m surprising to learn that U.S. Cellular is actually barely less friendly for pitchers than PNC Park. In fact, I am shocked to learn that in 2017, The Cell’s overall park factor shows it actually suppressed offense by 2%, while PNC by 4%. I always though of The Cell as a hitter’s haven. That perception was clearly driven by the home run factor, as one of the better parks for dingers in baseball. Meanwhile, PNC is one of the toughest to hit one out. But, the pitcher friendliness for homers at PNC is offset by The Cell’s advantage in singles, doubles, and triples. The Cell was also better for strikeouts, though it also raises walks. Last, The Cell is more favorable for both line drives and IFFB than PNC.

Overall, it would seem as if the park should benefit Nova’s BABIP, but increase his HR/FB rate. The homers are scary though as a move back to the AL could mean a loss of strikeouts, meaning more runners on, and more multi-run homers. With no strikeout rate upside to cushion his value, he’s an obvious avoid regardless of price and format.

Tanner Roark Traded to Reds

Remember when Roark significantly outperformed his SIERA in two of his first three seasons, leading us to wonder if he would consistently outperform his skills? So much for that idea, as he has either matched or underperformed his SIERA for the past two seasons.

Would you believe that in 2017, Nationals Park (NP) matched Great American Ballpark (GAB) in overall park factor, boosting offense by 4%? I’m sure you figured that GAB inflated offense by more and NP was neutral at best. GAB has the advantage in singles and doubles, but it’s drastically less pitcher friendly for triples and especially homers. This sounds a lot like what’s going to happen to Nova — perhaps a decline in BABIP, coupled with a jump in HR/FB rate.

GAB also inflates strikeouts, which could make it a bit easier for Roark to get his strikeout rate back above 20%. On the batted ball distribution, the parks are fairly close in line drive and IFFB factors, with GAB more favorable for the former and NP for the latter.

I have already updated my projection to account for this park change and overall, my ERA forecast increased thanks to the increase in HR/FB rate. In addition, unrelated to the park switch, but more the team switch, the Reds are supposed to stink defensively, so I bumped up his BABIP slightly. Though I prefer Roark of the three, that’s no ringing endorsement.