Lucas Giolito did not have a good game on Wednesday night against the Yankees. We can cut him some slack for giving up six of his seven runs in the second inning, but still, allowing seven runs in five innings is not the best look.
But should we view it as a predictable outcome for a pitcher with a 6.23 ERA facing one of the majors’ top offenses? Or can we see it as an aberration? If we look at Giolito’s last six starts, his profile is different enough from the one he built in his first 17 starts of the season that we may need to judge his recent and future results differently. Yes, six starts — and the 36 innings they comprise — represent a small sample, but the changes have been dramatic enough that they merit a closer look.
The most notable difference between the version of Giolito we have seen since his July 8 start at Houston and the one we saw beforehand is that he has been able to get chases on pitches out of the strike zone at a rate much closer to the major league average while freezing batters on pitches in the zone far more often than the typical major leaguer does.
|Time Period||O-Swing%||Z-Swing%||O/Z Ratio|
|Before July 8||23.7%||65.2%||0.36|
|Since July 8||29.0%||61.7%||0.47|
|2018 MLB Avg.||30.7%||67.3%||0.46|
Over his last six starts, Giolito has done a better job of getting swinging strikes, increasing his rate from 7.7 percent in his first 17 starts to a more respectable 8.9 percent. That still doesn’t make him a great pitcher for swings and misses, but he is working towards the next-best thing. Giolito is getting more swings on pitches that opponents have a harder time hitting well and fewer swings on pitches that more often lead to offensive production.
So having a high ratio of swings on out-of-zone pitches to swings on in-zone pitches is, as one would expect, a good thing. The graph below — consisting of all pitcher seasons of 80 innings or more since 2016 — shows the strong relationship (R-squared = 0.17, p < .0001) that exists between ratio of O-Swing% to Z-Swing% to wOBA allowed. Giolito’s O-Swing%/Z-Swing ratio before his recent stretch was 0.36. You can see by looking at the marks to the left of the line on the left that it is very hard to be highly effective with a ratio of 0.38 or lower. Of the 20 pitcher seasons with a ratio in that range, only two resulted in wOBA lower than .322.
Over his last six starts, Giolito has improved his O-Swing%/Z-Swing% to 0.47. That mirrors the year-to-year improvement made by Kyle Freeland this season, as is highlighted in the graph. He has boosted his ratio from .37 to .46, and among qualified starters, only Carlos Carrasco, Trevor Bauer and Patrick Corbin have had a more dramatic increase from 2017 to 2018. Freeland has an 8.4 percent swinging strike rate and an 18.9 percent strikeout rate this season, so like Giolito, he has needed to minimize the damage that hitters have made on contact. Getting a larger portion of his swings on pitches outside of the strike zone has helped him to do just that. His batting average on contact has fallen from .341 to .298 (per xStats.org), and his wOBA has decreased from .340 to .295.
Freeland has accomplished this by getting more chases on his changeup and more freezes on his four-seam fastball. The latter pitch is roughly as effective as it was last year, but the former has become a better swing-and-miss pitch (SwStr% is up to 10.7 percent, as compared to 8.0 percent in 2017) and has yielded a 46-point decrease in wOBA. Freeland has been throwing more of both pitches while phasing out his sinker, against which hitters have composed a .352 wOBA over the lefty’s career.
We may be tempted to credit Giolito’s recent improvement to an increase in fastball velocity, but his more frequent forays into the 94-97 mph range began three starts before the decisive change in his O-Swing%/Z-Swing% ratio. However, there were a couple of drastic changes that took hold at the same time his O-Swing%/Z-Swing% ratio started to surge upward. Like Freeland, Giolito started to throw his changeup more frequently. Over his first 17 starts, Giolito’s usage rate was just 12.3 percent, but since then he has raised it to 21.5 percent. Also, his changeup now has more horizontal movement. It’s hard to miss the trend dating back six starts in the graph below.
It’s worth re-stating that six starts is a small sample, and as such, may prove to be a forgotten, brief episode in Giolito’s career. It doesn’t mean owners should instantly check the waivers in all leagues to find and claim him. It does mean that every Giolito start will be worth tracking, at least until he stops doing a better job of inducing chases and freezes. If he continues on this path for the season’s final seven weeks, he could project to have similar value to the 2018 version of Freeland when 2019 arrives. (While he probably won’t have Freeland’s 82.1 percent LOB%, he should get more than the 3.6 runs of support per nine innings that Giolito’s Rockies counterpart has received.) As much as it clashes with his year-to-date numbers, it is not unthinkable that Giolito could be a top 50 starting pitcher next season.
Al Melchior has been writing about Fantasy baseball and sim games since 2000, and his work has appeared at CBSSports.com, BaseballHQ, Ron Shandler's Baseball Forecaster and FanRagSports. He has also participated in Tout Wars' mixed auction league since 2013. You can follow Al on Twitter @almelchiorbb and find more of his work at almelchior.com.