Starting Pitcher GB% Decliners — Apr 22, 2021, A Review

Yesterday, I reviewed the starting pitchers who experienced an early season GB% surge to find out if those spikes were sustained over the rest of the season. Today, let’s now review the early season GB% decliners. Did their GB% marks rebound or remain down, increasing the risk of gopheritis? Let’s find out.

Every single pitcher increased their GB% over the rest of the season from their down early season mark. Six of the eight increased their marks by double digit percentage points. I highlighted the Diff column in red if the pitcher was still down at least 5% in GB% over the rest of the season, even if that was an improvement from early on. That amounted to three pitchers. Two pitchers actually ended up posting a higher GB% over the rest of the season than they did in 2020. Once again, this analysis is limited as it’s reviewing metrics over a small sample and also only includes eight pitchers. So we can’t conclude anything concrete, aside from remembering that crazy things sometimes happen over the first couple of weeks of the season and it’s best not to overreact.

Jake Arrieta was one of three whose early GB% decline was a sign of things to come. As a low strikeout guy, more fly balls are a major negative, and sure enough, combined with an absurd 23.3% HR/FB rate, his HR/9 jumped over 2.00 for the first time in his career. After being DFA’d, his career may be over.

After a ridiculously low FB% early on, Max Scherzer was back to normal and finished the season almost exactly where he finished last year. But while he has always been a fly ball pitcher, this was the highest FB% he has posted in his career. As a high strikeout guy, it’s not really an issue as the homers are still not too high and all those flies have resulted in a low BABIP most seasons.

Zack Wheeler just missed my arbitrary cutoff to highlight the Diff cell to indicate the early season GB% drop was a sign of things to come. His rest of season mark remained below his 2020 mark, but not significantly so. Of course, like many on these lists, Wheeler’s GB% spiked to a career high in 2020, so the drop this year wasn’t so much losing ground-ball inducing ability, but regressing toward his career average. This was actually the third highest GB% he has posted in a season. After the best year of his career, his price will probably be more expensive than ever, which means he’s highly unlikely to be joining a Pod roster.

It doesn’t really matter too much if Jacob deGrom is generating grounders or flies, but he went from extreme fly baller early to a higher GB% than he’s ever finished with over a full season previously. He’ll be a risk coming off a season cut short by an elbow injury, especially as he turns 34 mid-season.

Yu Darvish was another of the three I highlighted, whose FB% was down all season long. He ended up easily posting the highest FB% of his career, which was made worse by a HR/FB rate that jumped back into the mid-teens and a strikeout rate that slid back below 30%. His age and injury history are a concern, but he significantly underperformed his SIERA and might actually come at a reasonable price next season.

Yusei Kikuchi suffered from a severe bout of gopheritis, so he needed as many grounders as he could induce to keep the homers to a minimum. That early season mark provided a scare, but he was back to normal the rest of the way. His fastball velocity spike has boosted his strikeout rate, but whether it’s a low LOB% (2020) or high HR/FB (2021), there has been something preventing him from becoming a real mixed league asset.

You don’t care about Jordan Lyles, right?

Sean Manaea’s early season GB% served as the biggest warning of a decline over the rest of the season out of the pitchers on this list. While his rest of season mark did increase, it did so by the smallest margin and it remained well below his 2020 mark. That said, his 2020 mark itself represented a career high and his mark this season was merely a drop back to around where he had always sat previously. The big question here is whether he could maintain that strikeout rate surge.