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Yordano Ventura's curve took a turn toward slider

Come for the curveball, stay for the charts.

Thomas B. Shea-USA TODAY Sports

Last season was weird for Kansas City Royals starter Yordano Ventura. Beginning the year with a large amount of hype, he struggled until a thumb injury on June 12th sent him to the disabled list. He would return to make one start before the All-Star Break (July 9th), before being optioned to the Triple-A Omaha Storm Chasers following another start on July 20th — being demoted in order to open a spot for Jason Vargas to return from the DL. This move wouldn’t last, as the baseball gods decided that they would like to see Ventura back in the bigs before he even got the chance to throw a pitch in the minor leagues. Two days later he would be recalled following a start in which Vargas left with an injury that would send him back to the disabled list, this time with a torn UCL.

After this odd sort-of-but-not-really send down, Ventura would pitch well, owning a 3.10 ERA and 3.40 FIP while improving his strikeout rate. Although he would also see a rise in his walk rate across his final 87 innings, he pitched better and would remain in the majors for the rest of the season, winning a World Series ring to top it all off. That general overview probably didn’t do his quirky 2015 campaign justice, but that isn’t what you came here for. No, you came here because of his quirky curveball — which, oddly enough, played a large role in his quirky season.

In case you were unaware, or maybe you just forgot, Ventura throws gas. Well, I mean he doesn’t actually throw canisters of gasoline, or tanks of gasoline, or cupped-handfuls of gasoline. You can blame science for that (stupid science, you never let us have any fun). So although he doesn’t literally throw gas, he does possess the ability to throw a baseball undeniably hard. When you think of Ventura’s stuff, this is probably the first thing that comes to mind. Although you might be thinking about his fastball, that quirky curve isn’t too shabby in this department either. In fact, it has been one of the fastest benders in the American League since his first full season in 2014.

A lot has been made of Ventura’s heat. We in the ‘getting impressed online’ business have discussed his blazing fastball ad nauseam, and for good reason. Through the course of his rookie season in 2014, Ventura threw a fastball or variation of a fastball over 70 percent of the time, as any young pitcher who owns that type of velocity would. It is a huge part of his game, but if you’re looking for a reason as to why Ventura finished pitched well in the second half, look no further than his curveball.

Following the odd performance his curve had in 2014 (which we shall discuss later), during the first half of last season the 24-year old attempted to add more vertical break through an increased spin rate — all while keeping velocity, spin angle, release point, etc. generally the same. Making his already impressive-to-the-eye curve more curveball-y would not be an adjustment that would stick for Ventura, as he would opt for a new type of curveball to start the second half of the season. As opposed to continuing down the loopy path (side note: can you actually call an 82.8-mph curveball loopy?) he had taken his 12-6 curveball, the hard-throwing righty decided to go in another direction.

He threw it harder:

Adjusted the way it spun:

Season Average Spin Axis (Degrees) Average Spin Rate (RPM)
2014 21 1056
2015 (1st half) 22 1214
2015 (2nd half) 30 1073

Added more horizontal movement:

And lessened its vertical movement:

This newer curveball would be what Ventura stuck with the rest of the season, but what he did to it was interesting to me. Instead of continuing to develop it as a pure overhand 12-6 curveball, he turned it into something that greater resembled a slider. It didn’t go full slider, but it definitely took steps in that direction. Yes, you can see that through the change his curve underwent movement-wise and spin rate-wise; in this case, however, the change in spin angle is the smoking gun.

All the change in spin angle means is that Ventura was able to get the pitch to spin more horizontally than it had previously, and this is something typically done on sliders. By moving towards the outer portion of the baseball, as opposed to over the top, pitchers are able to get this increased slider action — and Ventura is no exception.

In order to help facilitate this change, Ventura also lowered his release point vertically and extended it away from his body horizontally. While this change isn’t humongous, it further points to the fact that the young righty attempted to get outside the ball instead of on top of it. By using a new release point to affect his spin angle, Ventura was able to not only throw the pitch harder, but also add more horizontal movement — two qualities that caused the pitch to look more slider-esque, lest we also forget that we know sliders to own, on average, lower spin rates than curveballs.

So while the changes to the pitch itself were small and, when watching Ventura pitch, not overtly noticeable, there was something clearly different about the pitch in terms of usage. The difference? He threw it a whole lot more than he ever has. Obviously an increase in overall curveball usage would indicate that he trusts the pitch more, but that doesn’t necessarily tell the whole story. Over the course of his first full year and a half in Major League Baseball, Ventura used his curve almost exclusively as an out pitch. Then, post All-Star break, that began to change.


The fastball-reliant Ventura started throwing his curveball as more than just an out pitch, and we saw him begin to work backwards to hitters. It’s not every day you see a pitcher with triple digit heat in his back pocket decide to throw a curveball in a fastball count, and this is where you can really see that Ventura finally gained confidence in a curveball at the major-league level.

By now, you’re probably wondering how all of this translates to the field. Did this new curveball have more success than previous versions, or was it just an adjustment that went wrong? To answer that question, here is how it looked in comparison to the previous two versions according to Brooks Baseball:

Season AVG SLG ISO GB/BIP FB/BIP Whiff/Swing% wCB
2014 0.172 0.336 0.164 51.47 25.00 33.69% -3.9
2015 (1st half) 0.200 0.273 0.073 46.67 26.67 43.82% -0.2
2015 (2nd half) 0.137 0.180 0.043 69.35 8.06 42.62% 10.8

Let's begin with 2014. If you think Ventura’s curveball was weird that year, you’d be right. On one hand, the pitch owned a below-average run value in terms of pitch type linear weights. On the other hand, hitters didn’t do all that much damage to it when they put it in play. It’s tough to say that his curveball pitch was awful that season because of how many runs it was worth in terms of pitch type linear weights, but it would also be tough to say it was all that good.

Pitch type linear weights can be weird sometimes, and one of their huge limitations is that they aren’t able to account for pitch sequencing — meaning that, because Ventura used his curve as a setup/out pitch, it does not get evaluated accurately. Say he throws a curveball for a ball in the dirt on 0-2 in order to set up a fastball, which he then uses to strike out a hitter. The curve doesn’t get any credit for helping set up the strikeout, although it played a crucial role, and is instead charged with a negative run value because every pitch thrown for a ball always shifts the possibility of a run being scored in favor of the hitter. That being said, outcome metrics don’t account for anything other than when a certain pitch ends an at-bat, which excludes many of the pitches a pitcher throws. It’s complicated, it’s messy, but it’s probably safe to say that Ventura’s curveball was generally ineffective in 2014, while not doing all too poorly in the first half of 2015.

Then came the second half of last season, when we saw much different results. As a result of Ventura pitching lower in the zone with his curveball, he was generating a whole lot more groundballs. I mean a bunch. As in more than he had ever seen on his curveball before. As in, according to Brooks Baseball’s z-scores, two times more than the league average. Combine that with a greatly diminished FB/BIP total that had fallen under ten percent, and it would make sense as to why hitters lacked any power what-so-ever on the pitch.

Oh yeah, and his pitch type linear weights actually matched what his outcome stats were saying. Could it have been the result of him using his fastball to set hitters up and/or act complementary to his curve? Of course it’s a possibility, but the main thing that should be taken away is that his wCB was reflective of how effective the adjustments that Ventura implemented were, and the benefits he saw from increasing the amount he used the pitch.

So, in the end, Yordano Ventura had success with this new variation of his curveball that looks an awful lot closer to a slider. He found a way to improve his repertoire in a short amount of time through some seemingly-small adjustments that ended up having a large impact. Going forward next season, look at his velocity and check for an increase in movement horizontally. Watch for post-game quotes or newspaper articles that mention "Ventura" and "slider" in the same general vicinity. Who knows, maybe next season he will decide to go full slider — but would it matter? His new pitch fits the basic mold already.

--Spin stuff taken from Texas Leaguers

--Pitch usage data taken from Brooks Baseball

--Velo and movement charts taken from Baseball Heat Maps

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Shawn Brody is a contributor for Beyond the Box Score as well as a sophomore pitcher at Howard Payne University majoring in Business Management. If you would like to get a hold of him, please feel free to email him at or follow him on Twitter @ShawnBrody.