clock menu more-arrow no yes mobile

Filed under:

Lucas Giolito, and the return of the super prospect

From can’t-miss to afterthought, the righthander has made himself into an important piece of the rebuild, again

Chicago White Sox v Toronto Blue Jays
Plot twist: Lucas Giolito has turned himself into a pretty darn good pitcher so far this year.
Photo by Tom Szczerbowski/Getty Images

Well, well, well, who is the best pitcher on the Chicago White Sox staff at the moment? None other than Lucas Giolito. True, being the best pitcher on the White Sox is not a big accomplishment right now, but Giolito’s career with the club has been a whirlwind so far. Let’s recap.

The trade for Giolito was made Dec. 7, 1941, er, no, that’s something else. It was Dec, 7, 2016, and he was coming off an unfortunate first stint with the Washington Nationals — an 8.21 FIP in six games. With the White Sox in 2017, he was iffy in Triple-A but looked really solid when he was called up to big club, with a 2.38 ERA.

However, Giolito fell, and fell hard, in 2018, with a huge decrease in velocity to start off the year. He was able to have some success down the stretch — but the top prospect luster was gone. So far this season ... well, let’s take a closer look. But first, the visual change.

There is a noticeable difference, and that has led to noticeable results on every single one of Giolito’s pitches. If videos aren’t your thing (not sure why they wouldn’t be), well, graphs can also help with motions and release points.

Giolito’s career horizontal release point on the left, career vertical release point on the right, for all pitches.
Brooks Baseball

Sheesh, was 2018 a roller coaster ride. So far 2019 is much better, and cleaner.

The Fastball

The fastball is just night and day compared to this time last year, or really any time last season. On May 13, 2018, the average fastball velocity for Giolito per Pitch Info was 91.7 mph. In his last start, it was 94.1, a 2.4 mph improvement. In May 2018, the fastball had a spin rate of 2,050 RPM, and right now, the pitch is at 2,292 RPM, a 242 RPM increase. Yes, of course, I can provide a graph for that:

Giolito’s fastball by month since 2018: MPH on the left and RPM on the right.
Baseball Savant

Now, last season, Giolito’s fastball was terrible. Among pitchers with at least 160 innings pitched and using Pitch Info’s pitch value per 100 pitches, Giolito had the second-worst fastball in baseball. Though the 2019 rating is not in the upper echelon of MLB, it is ranked positively for the first time in his career. Just to add to that with a statistic, the wRC+ against Giolito’s fastball was 171 last season, and so far this year it has improved to 124. These improvements are largely because of the fastball velocity and spin increases — but what has it actually done?

Overall, Gioltio’s swing & miss is not a career high, but it has improved 5.2% from last season. That is the overall mark though, swings & misses on pitches both inside and outside of the zone. So far in 2019, the swing & miss rate of fastballs inside the zone have skyrocketed to a new career high.

Giolito’s in-zone swing & miss rate with his fastball per year.
Baseball Savant

With the added velocity and movement in the fastball Giolito can just blow past unsuspecting bats, especially because of how good his changeup has been so far, and the locations he can put his top three pitches (fastball, change, and slider).

Pitch location for Giolito’s fastball, change, and slider (left to right) in 2019.

All three seem to be working very well off of each other.

The Change

The changeup has steadily been one of the better pitches for Giolito in his MLB career, as Pitch Info has labeled it a positive pitch since 2017. Currently, it is the 15th rated change in MLB (min. 30 innings pitched), and as @PitchingNinja put it for Giolito’s start against Cleveland, it is “soul stealing””

Giolito’s change has not been much better in 2019 compared to previous years, but it has been more effective because he is putting it in tougher spots to hit than he ever has.

Giolito’s career edge percentage for his changeup.
Baseball Savant

As you were able to tell in the KDE heat map above depicting the pitch location of his change, it is low and near the edge of the strike zone a lot (51.4%, according to Baseball Savant). This pristine command has led to career bests in just about every batting-against statistic you can think of, even the expected stats.

But the real jump has been the K-rate of the change, as Giolito has continued to use it more often as a strikeout pitch. The K-rate has jumped almost 20% compared to last season, which is strange because the swing & miss rate has only increased 2%. However, Giolito is using the changeup about 11% more on two-strike counts in 2019 compared to 2018 (26.5% in 2018, 37% in 2019) and it is working much better, because the put-away % is at a new career high. How is the change working better? Well, Giolito is inducing about 9% more swing & misses with his changeup with two strikes, per Baseball Savant.

Giolito’s 2019 swing rate against the change with two strikes on the left, his contact rate against the changeup with two strikes on the right.

The change helped him get by last season. But really, the slider has been Giolito’s best pitch of 2019 — yeah, the pitch that was supposed to be his worst.

The Slider

At this moment, Giolito has Pitch Info’s sixth best slider (min. 30 innings pitched) in baseball. This is largely based on the huge increase of — you guessed it, after watching that slider above — swing & miss rate. In total, it has increased to 55.3%, and much of that comes from batters chasing and missing pitches.

Giolito’s chase and miss against the slider in 2019.
Baseball Savant

That matters a lot, especially since Giolito is throwing his slider outside of the zone more than ever before. But is there any difference in the slider besides Giolito’s new pitching motion and release points? Well, there’s a slight difference. While the slider has kept the same average velocity for three straight seasons (83.9 mph), the RPMs have slightly dipped and the pitch has more of a vertical tail, as you can see from the video above or the graph below. The slight difference has certainly worked for him.

Giolito’s vertical movement on his slider from 2018 to 2019.
Brooks Baseball

The added vertical movement is a big reason why of 88 sliders thrown this season, 79 have been against righties, and also why batters have a -33 wRC+ against the pitch in 2019.

Yeah, sure, the pitches are better, and the motion is crisper and more repeatable. But confidence is what Giolito needed in his pitches, and he has it in 2019.

The sinker he used in 2018 to salvage his season has not been used at all because his fastball has been so good. That’s confidence in the fastball.

The changeup usage is up 7.2%. That is confidence in his change.

Though the slider usage is down overall from 2018, the gap between the overall usage of his slider and curveball has widened by .5%, and the use of his slider against right-handed batters has increased by 12%. That is confidence in his slider.

Giolito is throwing 55.6% of his pitches inside the zone, and 62.8% of his first pitches for strikes. That is confidence in his ability overall.

All of these changes have created a much better pitcher, and the super prospect Giolito was tabbed as multiple years ago might be here to stay. But he will have to continue to repeat his new motion in order to keep that confidence intact.