Royals Spring Training camp officially begins on Sunday in Surprise, Arizona, with games taking place on Friday, March 18th against the Texas Rangers, as announced in the updated Spring Training Schedule (via Royals Twitter):
While we are still getting details about who will be invited to Royals Major League Camp, there are plenty of storylines to pay attention to at camp in Surprise, as I discussed in a post yesterday.
In a short series of posts, I am going to take a look at a particular pitch (or pitches) of a specific Royals pitcher who will be key in 2022. I will examine why it will be important to pay attention to that’s pitch usage in the Spring, in order to determine that pitchers’ short-term and long-term outlook in Kansas City.
In this post, I am going to take a look at Carlos Hernandez and his two breaking ball offerings: the slider and the curveball.
Carlos Hernandez and the Slider
Nick Pollack of Pitcher List did a pretty interesting deep dive into Carlos Hernandez yesterday, the last piece of his “Going Deep” series on some pitchers he was intrigued about going into the 2022 season.
One interesting area that Pollack focused on was Hernandez’s breaking ball arsenal, as he possesses both a slider and a curveball.
Both pitches are not stupendous pitches by any means, as he threw his slider and curveball 16.3 and 18.6 percent of the time, respectively, and both generate a run value of -3 (slider) and +2 (curveball) in 2021, according to Savant.
Here’s a look at how Hernandez’s metrics on his pitch arsenal broke down last year, and pay special attention to those curveball and slider numbers:

The slider generated a higher whiff rate and was a better put-away pitch, but he got luckier on the slider in comparison to the curveball in 2021.
The expected batting average (xBA) on his slider was 64 points higher than the actual batting average. That is the inverse of his curveball, as the expected batting average was 42 points LOWER than the actual batting average last season.
A big reason for the difference between the two pitches is that Hernandez’s curveball generated less hard-hit contact than the slider, 10.5 percent to be specific. That is not surprising, as Hernandez’s curve has a higher spin offering than the slider, which can be seen in the spin data chart below, via Savant:

Last season, Herandez’s curveball generated an active spin of 66 percent with 13.5 inches of total movement, which ranked him in the 41st percentile in 2021 (an improvement on the 28th percentile ranking in 2020). On the other hand, his slider only had an active spin of 26 percent with 4.8 inches of total movement. Both those marks were the lowest-rated pitches in those respective categories a season ago.
Now, the slider isn’t an awful offering by any means. It averaged 85.4 MPH a season ago, nearly 3.7 MPH faster than his curveball. When located properly, it can be an effective pitch, especially for hitters who are sitting on his changeup, which is around the same speed (86.5 MPH), or his sinker.
Here’s an example of Hernandez utilizing his slider effectively against the White Sox’s Zack Collins:
There isn’t a whole lot of drop on a vertical or horizontal end on the pitch, but it is located effectively by Hernandez. That inside part of the zone on left-handed hitters is an area where Hernandez would typically throw his sinker, as the tailing arm-side movement of the sinker would freeze a lefty who is thinking that the pitch may be initially a ball out of the hand (before it would tail in and paint the inside edge of the strike zone).
Here’s a look at what Hernandez’s heatmap looks like with the sinker against left-handed batters:

Now, let’s take a look at his slider location last year vs. left-handed hitters:

Thus, when paired with the sinker, the slider can be an effective pitch, when commanded effectively. When Hernandez made mistakes on the pitch though, hitters took advantage, as evidenced by this mistake to Houston’s Carlos Correa, who drove a mistake slider in the left-field seats at Kauffman Stadium:
The nice thing about Hernandez and his outlook as a starter long-term is that he utilizes five pitches in his arsenal, including four pitches that he throws more than 10 percent of the time.
Thus, if he does drop a pitch, or lessen the usage of one considerably (under 10 percent usage), that wouldn’t be the worst thing for him, especially if the increased usage tradeoff results in that pitch being more effective.
His slider could be one of those pitches eligible to see a decrease in usage in 2022.
Hernandez and the Curveball
We have talked a lot about the slider thus far, but we haven’t dug too deep into Hernandez’s curveball, which he threw 2.3 percent more than his slider in 2021.
What’s interesting about Hernandez’s curveball is that at first glance, it’s not necessarily impressive at first glance. After all, he posted a +2 run value on the pitch in 2021, and it wasn’t much better his rookie season, as his curveball generated a +5 run value while being thrown 24.7 percent of the time during the COVID-shortened 2020 campaign.
However, when it comes to collecting strikes, strikeouts, and a lower hard-hit rate, the curve proved to be a way more effective pitch than the slider.
Here’s a look at the Statcast data on his slider a season ago:

Now let’s get a glance at that same set of data, but this time in relation to the curveball:

The curveball did post a slightly higher walk rate than the slider last year, but the pitch also did produce a seven percent higher K rate, a 10 percent lower walk rate, and one fewer barrel as well (which included a zero percent HR rate to boot).
When it came to generating CSW (called plus swinging strikes), here’s what Hernandez’s heatmap looked like from 2021:

As Royals fans can see, the two deep-red dots, which signify the frequency of the location of the pitch on the heatmap, are in the middle and down glove-side, respectively. The middle dot tended to be more called strikes, and the low and away red dot tended to encompass more swinging strikes.
What’s interesting to note is that even though he threw that curveball a lot in the middle of the zone, hitters didn’t do major damage against it in terms of barrels and home runs, especially from the right side of the plate.
In fact, when he threw the curve in zone 5, most of the right-handed hitters who made contact fouled it off, as evidenced in this at-bat against Texas’ Adolis Garcia:
And heres’ something similar happening to the White Sox’s Andrew Vaughn in August:
That being said, it seemed like left-handed hitters were able to see and connect on that pitch when thrown in that part of the strike zone.
Here’s an example of Jorge Polanco absolutely driving Hernandez’s curve which is hung in the middle of the zone, though thankfully it stays in the ballpark at Target Field:
Therefore, while command of the curveball will still be a priority this spring, it will be interesting to see if Hernandez will vary the usage of his curveball depending on the hitter he face (i.e. what side of the plate he is hitting). The curveball, with its higher-spin movement, appears to be more effective against right-handed hitters.
However, against lefties, it can be picked up easier, especially when it is thrown in the middle of the zone. Thus, when facing left-handed hitters, Hernandez could opt to use the slider more, which pairs better with the sinker, which typically is also thrown more against left-handed hitters (with the four-seamer thrown more against right-handed hitters).
A more discerning usage of the curveball going forward could perhaps result in a closer difference between that actual and expected batting average next season.
Final Thoughts
The big question for Hernandez this Spring will be if Royals fans will see some tradeoff between his slider and curveball this year. Will he utilize his curveball more, which had less batted ball luck last year, but generated a better K rate and CSW rate (29.2 percent to the slider’s 28.1 percent)?
Or will Hernandez prefer the slider more, simply because it’s a higher velocity offering, and plays better off his sinker, especially against left-handed hitters?
Both pitches have their pluses and minuses, and I am not advocating for Hernandez to completely eliminate one from his arsenal. The curveball plays better against right-handed hitters, while the slider is more effective against lefties, and Hernandez could play that pattern to his advantage next season.
That being said, I think Royals fans will see Hernandez increase the usage of one breaking ball offering and regress in the usage of the other, as a result, in 2022. After all, being more efficient with his pitch mix will not only make Hernandez’s pitches more effective but make him a better pitcher overall in the long term.
Though as of now, it’s anyone’s guess which breaking ball will see the increase (and vice versa, the decrease).
Photo Credit: Denny Medley-USA Today Sports