Lucas Giolito has looked like a different pitcher this season, particularly over his last five starts, where he has posted a miniscule 1.67 ERA in 27 innings, striking out 32 and walking only 9. But even if you take his entire 2019 body of work into account, he has been so much better through eight starts than he was in 2018.
Of 109 pitchers who entered Sunday with at least 40 innings pitched, 24 of them are averaging 10 or more strikeouts per 9 innings, and Giolito is one of them, at 10.47. Giolito finished 2018 with 6.5 strikeouts per 9 innings, which is far from ideal. Going by strikeout percentage, he's way up from 16.1 percent to 28.6 percent.
Comparing his first eight starts of the season in 2018 and 2019, the difference is staggering.
Lucas Giolito – first eight starts of season
Maybe the ERA stands out most to you, but to me, the strikeouts are much more critical.
But why? How is he doing it? The answer certainly seems to be the changeup.
Lucas Giolito first seven starts of 2018 and 2019.
Strikeouts by pitch type (pitch type data from Statcast)
Giolito over his first seven starts of 2019 recorded 16 strikeouts on his changeup, whereas he didn't record any strikeouts through seven starts last season. This shouldn't come as much of a surprise if you have watched him work this season. That pitch is nasty and hopefully it continues to be a weapon going forward.