The Chicago White Sox head into 2020 with some optimism. They have young stars, such as Yoan Moncada and Eloy Jimenez, and made some offseason splashes for Yasmani Grandal and Dallas Keuchel. Their pitching staff is going to be better this year, and Lucas Giolito is going to lead it especially after his breakout season. He made significant changes to how he pitches and today, I’ll show you those changes.
First off, I’d like to show exactly how bad Giolito was in 2018. He had a 6.13 ERA, a 5.56 FIP, and an xFIP of 5.46 to show that he wasn’t drastically unlucky. Of course, his batted ball stats were brutal too, he gave up barrels 7% of the time, batters had an average exit velocity of 88.4 mph, and they also hard-hit rate of 36.9%. These numbers are all horrifically bad, and he needed some massive changes to how he used his pitches, the rate at which he used them, and his arm slot.
Giolito made some big changes with his arsenal, which contains a four-seam fastball, a change-up, a slider, and a curveball. His pitch movement change from 2018 (left) to 2019 (right) is shown here (Brooks Baseball):
As you can see, in 2018, the movement on his pitches wasn’t very consistent. Most of the pitches changed month to month, so it could’ve been hard to command each of them as he’d have to adjust to how his pitches were playing over time. He also had a sinker that he used very minimally, but in 2019, it was ditched. Last year though, his pitch movement profiles ended up coming tighter together, his changeup was still a little spread out, but it was closer than 2018. Let’s look at each pitch to see how they changed individually.
The four-seam fastball was demolished in 2018, it had a .412 wOBA, a .415 xwOBA, to go along with a low whiff rate of 14.3%. His spin rate on it was 2099 RPMs, and had a spin efficiency of 86.7%, so the actual spin on the pitch was about 1820 RPMs. These numbers were below average for fourseamers and they translated to the movement profile of 8.87 inches of vertical movement and -4.38 inches of horizontal movement (catcher’s view). He needed to figure out how to get more lift on his fastball by increasing his spin rate and efficiency and that is exactly what he did as he increased both to 2333 RPMs and 91.2%, respectively. This lead to an inch and a half more vertical movement to 10.29 inches and the horizontal movement stayed about the same. The results showed that this pitch was better: a .281 wOBA, a .287 xwOBA, and a 26% whiff rate. He also used it in a different way that may have affected the results. He decreased his usage from 59% to 54%, which isn’t huge but it is something to throw out there, but he also changed the pitch location of it (Savant):
In 2019, Giolito ended up going with the trend of pitchers today and threw the four-seam up in the zone more frequently. This went along with the pitch getting more lift to it and batters would swing underneath it more often.
The changeup underwent changes as well. First of all, he actually lowered his total spin rate on it from 1651 RPMs to 1563. This didn’t lead to less movement though, because while he decreased his spin, he really added it because he increased the spin efficiency from 72.4% to 83.7%. The useful spin of the two pitches was 1308 in 2019 and 1197 the year before. This created more movement on the change-up as he added about two inches of lift as the vertical break went from 4.77 inches to 6.59 inches, and the horizontal break actually went down from -6.1 to -5.81, I'll talk about why the movement profile changed later. Here is the pitch location chart of the changeup:
It seems as though he threw his changeup a little bit higher in 2019 as well, he also threw it more towards the middle of the strike zone. This could’ve been because the pitch added rise and so he wanted to do the same thing as the fastball and hopefully generate more swings underneath the pitch. He also increased his usage of changeups by 10% to using it 26% of the time. This lead to a decreased wOBA from .282 to .270 and a decreased xwOBA from .302 to .252. He also generated 6.5% more swings and misses.
His slider is also a very good pitch as the whiff rate was 42% compared to 36.3% in 2018. However, hitters had a better time when they actually hit it in 2019, as their wOBA increased by .02 to .251 and their xwOBA increased by .022 to .266, hitters didn’t hit the ball harder though, as their average exit velocity went down to 86.1 MPH from 86.5 MPH. The pitch changed as the White Sox got him to create more efficiency without changing the spin rate much. The efficiency went from 21.5% to 27.9% which translated to 1.5 inches more vertical movement to 2.88 inches and .18 fewer inches of horizontal movement to 1.64 inches. The low numbers of movement are due to the gyro spin on the ball, and when he actually throws it, the ball ends up moving more than said here. This is due to the ball getting more vertical spin efficiency as gravity pulls it down. Giolito used the slider about the same amount as he did the year prior. Here are the heatmaps of his sliders (Savant, Left: 2018, Right: 2019):
It appears that he started to pitch the ball low and to his glove side more in 2019, while in 2018, the pitches had two distinct spots: one towards the heart of the plate and the other on the low glove side. He was able to generate more swings and misses as he was keeping the ball on the paint.
The curveball was his least used pitch, and rightfully so because it is by far his worst one. While he increased the spin on it by almost 200 RPMs and got an extra inch of vertical break, the pitch was actually hit harder by an average of 5.7 MPH to 92.6 MPH. That led to a wOBA of .426 and an xwOBA of .475 on the pitch, which is obviously very bad. Here are the curveball heatmaps (Savant, Left: 2018, Right: 2019):
That 2018 chart is all over the place, it seems as though he wasn’t really able to control the pitch very well, it seems like it is very spread out in 2019 as well, but with a much smaller sample size since he threw the pitch less. The curveball was probably hit harder in 2019 as the bulk of the pitches were located close to the middle of the zone, compared to the 2018 chart where a bunch of the pitches ended up out of the zone on the glove side.
Pitch movement has a lot to do with the spin axis of the baseball as well, so here is a chart showing how Giolito's spin axis changed (Brooks Baseball):
These charts have vertical release point on the y-axis as I wanted to keep all of the pitches closer together so they'd be easier to compare. The average spin axis for his curveball and four-seam didn't change much year to year, while the slider changed from 151 degrees to 163 degrees and his change up changed from 231 degrees to 220 degrees. Both of these changes in spin axis led to more vertical lift for both of the pitches as the axis got closer to the 12 o'clock spin, which is ideal to get the most vertical lift or break. Not only did those spin axises change, they got more consistent last year. You can see this as the dots for each pitch are more bundled together with their pitch types. This would help Giolito command the ball more consistently as he would know better where the pitch is going to end up.
Another thing that Giolito needed to fix was the consistency of his release point. Here are two charts showing the change in his release point from 2018 to 2019 (Brooks Baseball, Left: 2018, Right: 2019):
The two seem to be polar opposites of each other as Giolito was able to fix this problem. His arm slot varied from month to month with all of his pitches in 2018, and it really shows in that chart. While last year, it was very hard for hitters to tell what pitch was coming right out of the hand as they release points were all clustered up. That benefits all of his pitches due to that reason.
We all know what happened to Giolito after all of these changes, but I am going to just give a quick overview of his successful season last year. He struck out 32.3% of hitters he faced compared to 16.1%, his FIP went down by 2.13 to 3.43, his xFIP was 3.63 to show that was not much of a fluke, and both his wOBA and xwOBA went down by .07 to .275 and .280, respectively. One thing that he was actually pretty average at, though, was getting hitters to make weak contact as his average exit velocity against was at the 54th percentile and his hard-hit rate against was at the 65th percentile. While his exit velocity was pretty average, it was a lot better than the year before, and his above-average hard-hit rate had gotten better as well. He also struggled with minimizing barrels, as he was only in the 14th percentile last year and he was actually in the 38th percentile the year before. Although that number wasn’t great, he was able to stay great by generating whiffs and not letting teams make contact against him.
Lucas Giolito and the White Sox are both very young and up and coming. They have extremely bright futures ahead of them, with Giolito only being 25, he is only going to get better and that’s pretty scary. He has the potential to be one of the premier pitchers in the game and last year was a huge jump for him to get to that point.
I did one a post similar to this one with Gerrit Cole a couple of months ago. If you want to read it click this: https://kaifranke.wixsite.com/mysite/post/gerrit-cole-pitch-design
Pitch movement, spin axis, and release point charts are from Brooks Baseball
Batted ball data, x-stats (besides) xFIP, and heatmaps are from Baseball Savant
Performance stats are from FanGraphs
Cover photo via Bleacher Report
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