Lucas Giolito Is Saving His Season
Every spring training, we all know we shouldn’t read too much into results. And, every spring training, we all read too much into results. It’s not like anyone could blame us — during spring training, that’s the only baseball going on, so, what are we supposed to do? But this past spring training, I fell in love with Lucas Giolito, and it was mostly because of a dominant start he had against the Cubs. His stuff looked sharp and he’d altered his delivery, and it looked to me like Giolito might’ve been poised for a breakthrough season.
Then the actual season began, and Giolito might’ve been the worst starter in the bigs. For one thing, his stuff ticked down. And for another, in March and April, he had 11 strikeouts to go with 21 walks and four hit batters. May brought 19 strikeouts, to go with 16 walks and six hit batters. Giolito approached the end of June with an ERA over 7. He entered August with an ERA over 6. People wondered whether Giolito might’ve been better off getting demoted to Triple-A. It didn’t look like he was making any forward progress in Chicago.
You might’ve checked out. You might’ve focused instead on Michael Kopech. So let me fill you in on a recent development. Over five starts in August, Giolito has thrown 31 innings. He has 10 walks and 32 strikeouts, and he’s thrown close to two-thirds of his pitches for strikes. It hasn’t all been great, but it’s assuredly been better. Giolito might finally be taking a step forward. I’ll walk through some of the points that I find to be encouraging.
If nothing else, Giolito at least looks as good as he did late last summer. The following rolling-average plot covers Giolito’s brief major-league career, with five-game samples of strikeout and walk rates:
It’s readily obvious that recent Giolito has been the best version of 2018 Giolito. He’s been throwing far more strikes. He’s been missing far more bats. He’s also been generating far more grounders. Whatever you’d want, Giolito has been doing it, and perhaps unsurprisingly, Giolito’s stuff has also improved. Compared to the first month especially, Giolito has tapped into some arm-strength reserves. Witness the recovery of his fastball:
Giolito is working back into the mid-90s. When the season began, he was closer to 90-92. Remember that when Giolito was a prospect, he was considered by some to have the best fastball in the minor leagues. That same fastball hasn’t shown up for long stretches in the bigs, but it certainly can’t be a bad thing for the velocity to be bouncing back. It’s above league-average again, and I doubt this has anything to do with Giolito’s actual arm strength. Rather, I suspect the explanation is mechanical. Here’s a plot of vertical release points, from Brooks Baseball:
Giolito indeed began the year with a lower arm slot. But for as good as he looked in that start against the Cubs, the adjustment seems to have worked against him. As this season has gone on, Giolito has brought his arm back north, and he’s thrown harder and harder. Sometimes adjustments help a pitcher; sometimes adjustments hurt a pitcher. Giolito seems to be more comfortable and more powerful with a higher slot. There’s a little more, as well. Here’s a clip of Giolito facing the Twins in April:
And here’s a clip of Giolito facing the Twins last week:
For one thing, we can visually confirm the higher arm slot:
The difference isn’t huge, but Giolito’s elbow is higher on the right, instead of coming so much around the side. Beyond the release, though, there’s also the matter of Giolito’s follow-through. This is another comparative image set:
You can see it in the screenshots, and you can see it in the embedded videos from earlier. Giolito’s back leg used to do a lot of, shall we say, kicking — after release, his back leg would swing around with a kicking motion before momentum carried Giolito toward first base. Giolito’s leg doesn’t stretch out like that so often anymore. Perhaps relatedly, he seems to have a more controlled left arm and glove hand. Now, you don’t really teach someone’s follow-through. Instead, how a pitcher follows through reveals details of the earlier throwing motion. Giolito’s delivery seems to be cleaner, with fewer forces pulling him to either side. He visually looks to have a better finish, which would suggest he’s improved his balance and timing. It’s not a shocker that he’s throwing with better power and control. So much of good pitching comes down to efficiency.
At last, as Giolito has gradually figured out his mechanics, he’s also made some tweaks to his approach. He has a slider and curveball, but let’s focus on his fastballs and changeup for a moment:
Giolito used to be known for his four-seam fastball, and he still most certainly has that in his possession. But he’s also taken to more of a two-seam variety, and if recent performances are any indication, Giolito can hit the strike zone with his two-seam fastball with ease. Here is a very impressive visual of the pitch:
And as the two-seamer has come on, I have one final thing to show you. That last plot included the changeup. As Giolito has leaned more heavily on his two-seam fastball, he’s also changed his changeup to resemble the two-seam fastball more closely:
This past July, it follows that Giolito tweaked his changeup grip, such that it would have more horizontal break. This month, Giolito has gotten more comfortable with it. By and large, pitchers want to keep their changeups down in or below the zone. Through the end of July, Giolito’s average changeup wound up 2.3 feet above the ground. That was one of the highest averages in either league. In August, his average changeup has wound up 1.9 feet above the ground, an average drop of almost five inches from before. Giolito’s August average is around the middle of the pack, and what this means is that, lately, Giolito has been far more able to keep his changeup low. He’s not flying open and letting the pitch get away from him.
This is a lot of words and images about a pitcher who remains a work in progress. Giolito still has to prove himself, still has to prove he can stay ahead of his opponents, and then put them away. Again, I wrote good things about Giolito in March, and then he was dreadful. The mission isn’t yet accomplished. But Giolito, at least, is finding something in 2018 that he can be proud of. While he never got demoted to the minors, he seems to have taken steps to salvage what otherwise would’ve been a lost and tremendously disappointing season. Giolito, now, is throwing with a cleaner motion, and he’s throwing better stuff, with a better ability to locate. We know that pitcher development doesn’t follow predictable patterns. If it did, Giolito would’ve been an ace a year or two ago. Instead, he took some major steps backward. Now he’s making up ground in a hurry.
Jeff made Lookout Landing a thing, but he does not still write there about the Mariners. He does write here, sometimes about the Mariners, but usually not.







Good Article Jeff. Sox fans have been following his progress closely, he has really turned it around over his last 7-8 starts. August, in particular, has been a very encouraging month.
super interesting and timely, would you take Giolito over, Eovaldi at this point?
sorry if my comments are bad …. i guess
Thanks for the recent attention to Sox pitchers. I’m hoping the 4 young guns can all be worthy of rotation spots even if none of them break out.
SP – Rodon, Kopech, Giolito, Lopez, Cease, Dunning
BP – Burdi, Hamilton, Fry, Frare
Eloy
This is what brings a smile to the faces of White Sox fans this dismal season.
Yes. Fulmer could also be a useful bullpen piece if he can ever throw the occasional strike.
Also, Madrigal, Robert…maybe Burger? Maybe Collins for different reasons? I wish they had more hitters.
DAMN is that a filthy fastball. Goes from looking like a ball to almost dead-center horizontally.
For the past few years I have been following the career of Lucas Giolito and how closely it resembles that of Byron Buxton, only from the pitching side. Both were not just prospects, they were the best of the best and they have had remarkably similar careers up until now. Disappointing is a gross understatement with both. Buxton teased the baseball community late last year with a surge that gave hope that he was emerging from the fog but this year has been even worse than ever. But, as he has in the past, he is tempting us again by going 9 for his last 16 and 17 for 44 in the last 10 games. Giolito ‘s failures have been well-documented. His stuff just disappeared. Now we have to find out if this is just another mirage. It is much easier to measure the velocity of a fastball than it is to dissect the mystery that is the ability to barrel said fastball. The numbers look encouraging for Giolito but please excuse me if I wait until next June or July to render my decision.
Fantastic article! Do you think his change in arm angle could have anything to do with growing confidence in his health as his Tommy John surgery becomes more of a distant memory?
I’m glad the Sox didn’t give up on him. I know they didn’t have tons of options ready to steal his spot or anything, but he still factors into their long term plans and they did well to let him work through it, I think.
This is an awesome article. He was the worst pitcher in baseball from April through July but Don Cooper is a miracle worker. I’d love to see someone try to calculate the wins Coop has added by turning around pitchers in Chicago.