Mixing It Up: Yoshinobu Yamamoto's and Framber Valdez's slider

Even though Spring Training is long behind us, we have no reason to stop looking into pitchers throwing new pitches. In fact, this is when the fun begins. Many pitchers will test new pitches in the spring but abandon them when the regular season starts. It can often be more informative to see which pitchers have drastically changed their pitch mix or pitch shape after a few starts in the regular season.

With that in mind, we will continue with the premise of the series I had called Pitchers with New Pitches (and Should We Care) by breaking down notable changes in a pitcher's pitch mix (hence "Mixing" it up). We'll look at pitchers who are throwing a new pitch, have eliminated a pitch, or are showcasing a different shape/velocity on a pitch.

I'll continue my analysis with the simple premise that not every new pitch should be greeted with praise. A new pitch, like a shiny new toy, might be exciting on its own, but it also needs to complement what a pitcher already has and fill a meaningful void in his current pitch mix. We want to check and see if he has any splits issues. We want to see what his best pitch(es) is and see if this new pitch would complement that. Then we want to see what this new pitch type is generally used for (control, called strikes, etc.) and see if that is something this pitcher needs help with. We can also now see the pitch in action to look at the shape and command and see if it's actually any good. Once we've done all that, we can decide if the pitch is a good addition or not.

If you missed any of the previous editions of this series, you can click this link here to be taken to the tracker, which I'll update as the season goes on. It also includes links to the original articles so you can read them in full if you'd like.

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Yoshinobu Yamamoto - Los Angeles Dodgers (Slider)

There's been a lot of hand-wringing over Yamamoto this season. After he was the second biggest name on the free agent market and signed a lucrative contract with the Dodgers, there was some expectation that he would come in and set the league on fire and, I guess, the 2.79 ERA and 28% strikeout rate haven't done it for people. I've even read comments that he's "Lance Lynn with strikeouts," which doesn't quite make sense but here we are.

Perhaps the biggest talking point for Yamamoto has been the performance and location of his four-seam fastball, which is getting hit a bit harder than it should because he's not locating it up in the zone, where its shape suggests it would have the most success. However, we're not here to talk about that; we're talking about new pitches and pitch mix changes. (And, for the record, Yamamoto did start to go upstairs with the fastball on Tuesday against the Marlins. The graph below is all his whiffs on the four-seam and you can see just how many of them are located up).

Early on in his MLB career, Yamamoto has had pretty shocking reverse splits, fairing way better against left-handed hitters than righties.

While we should acknowledge that we're dealing with a small sample size, it's worth looking into WHY this might be the case.

For starters, despite having a 33% strikeout rate to lefties and a 26% strikeout rate to righties, Yamamoto actually has a higher swinging strike rate (SwStr%) versus righties, which suggests getting swings and misses isn't the issue. His four-seamer is his most used pitch to hitters of either-handedness, and it has a 12.2% SwStr% to righties and just a 4.1% SwStr% to lefties. His splitter also misses an equal number of bats to righties and lefties and he uses it in two-strike counts over 50% of the time to both, so there's no issue there. The big thing is that Yamamoto's curveball performs better as a two-strike offering to lefties, posting a 42% PutAway rate, which is how often a two-strike pitch results in a strikeout. It has just an 18% PutAway rate to righties. That's a major difference.

The other issue is that righties hit Yamamoto's four-seamer much better than lefties. The pitch doesn't miss bats against lefties, but it has just a 25% Ideal Contact Rate (ICR) and a 12% barrel rate compared to a 50% ICR and 22% barrel rate against righties. A big thing is location. Yamamoto has thrown 36% x-middle fastballs to righties, which means that instead of hitting the outside part of the plate or going inside on the hands, the fastball is over the middle of the plate. That number is just 25% against lefties. He also has thrown a shocking 17.3% of fastballs middle-middle to righties. The league average is 7.8% so that's a horrible number.

So what we can take away from all of that is that Yamamoto could use another pitch to righties that can keep them off his fastball but also perhaps help him miss some more bats in two-strike counts. Maybe the answer is a slider that Yamamoto used for the first time in his MLB career two starts ago, throwing the pitch just three times, all to righties. Fabian Ardaya confirmed the introduction of the slider in his article in the Athletic, where he quoted Austin Barnes saying “'I think it’s an interesting pitch for him.' Yamamoto confirmed that he threw a couple of sliders in his final inning through interpreter Yoshihiro Sonoda, though he remarked the pitch was 'nothing special.'"

Yamamoto then threw the pitch six times against the Marlins on Tuesday, throwing just two of them in the strike zone but getting four swings and one whiff. It was a better effort than the first start but still not something eye-catching.

Yamamoto's slider is a harder slider at 86 mph that has just 7.4 inches of horizontal movement and 4.4 inches of drop. The pitch graded out with just a 4.06 PLV at Pitcher List (where 5.26 is league average), so that's not overly enticing but it's just nine pitches.

In reviewing all pre-season pitch mix analysis articles on Yamamoto, my favorite being Eno Sarris’ piece in The Athletic, it seems like the slider was not something he used much, if at all, in Japan. Perhaps he's using it as a variation on his cutter, which he mostly throws to lefties. Yamamoto's cutter is 91 mph with just 2.7 inches of horizontal movement and eight inches of drop, so the slider is five mph slower and with more horizontal movement. Considering Yamamoto throws his four-seam low in the zone, a slider that could tunnel with the fastball but break away from righties, since the splitter breaks in, could be a solid offering for him.

Yet, at this point, it's hard to know if the slider could be that pitch. The cutter has missed bats with a 21.4% SwStr% to lefties, so a version of that to righties does make some sense, but the cutter also grades out as Yamamoto's worst pitch and has been hit hard, so it's unclear if a version of that is going to be something that makes a huge difference for him.

VERDICT: MINIMALLY IMPACTFUL. If Yamamoto were to add another pitch that he could throw for strikes against righties and also miss some bats with, that would obviously be a good thing. Especially if it works well with the four-seam and can limit some of the hard contact on his main offering. However, everything in Yamamoto's profile just screams to me that fixing the four-seam is the only thing that will make an impact on taking him from a really good pitcher to a great one.

Mitchell Parker - Washington Nationals (Slider)

Mitchell Parker is a funny dude. In his first career MLB start, he threw 94% four-seam fastballs and curveballs and mixed in just a few splitters. In his next start, he surprisingly threw 21% splitters and also three sliders. A fourth pitch? In his third start, he actually threw more splitters than curveballs and threw two more sliders, and then in his next start, he threw six sliders that were also 1.5 mph harder than the ones he had previously showcased.

While we love seeing young pitchers expand their arsenal and attack hitters in different ways, we also have to ask: who the heck is Mitchell Parker actually and what's the best approach for him?

After digging into his pitch mix, it seems to me that Parker is still a four-seam/curveball pitcher who will use his splitter against right-handed heavy lineups and his slider against lefties. In fact, Parker has not yet thrown a splitter to a lefty and hasn't thrown a slider to a righty. So can this approach work?

In short, I think it can against right-handed hitters, but it seems like Parker may be emerging as another reverse-splits pitcher who will struggle against lineups that feature a lot of lefties.

For starters, the fastball gets hit much harder by lefties with a 50% ICR compared to a 38% ICR for righties. That's interesting because he throws the four-seam up in the zone more to lefties and throws it middle-middle far less often. Perhaps it's because he keeps the fastball away slightly more against righties, but I think it could also be that the four-seam pairs better with the splitter that he throws to righties while the slower and loopier curve is easy to pick up out of the hand. In that sense, lefties would more easily be able to see the curve on release and since he only has the curve and fastball to lefties, they can sit on the pitch more.

That might be supported by the fact that Parker's curve misses far fewer bats against lefties with a 5.7% SwStr% compared to a 14.5% mark to righties. Lefties don't hit his curve particularly well, but the limited arsenal to left-handed hitters means they're fooled less often and are doing damage on that fastball. In that sense, the increased use of the slider to lefties would make sense.

However, so far, we haven't seen the slider work all that well in a limited sample size. It has just a 4.46 PLV grade, where 5.26 is average, and he seems to have trouble commanding it, with just an 18% zone rate and 27% strike rate. The pitch has a solid eight inches of horizontal movement, and he's clearly trying to keep it away from lefties, which is good, but he's also throwing it high in the zone almost 37% of the time, which seems to make no sense. Again, it points back to command for me. Thus, the idea works, but the execution isn't even close to there right now.

VERDICT: POTENTIALLY IMPACTFUL. Parker needs another pitch to lefties and the slider could be that. However, right now it's hard to get excited about a new pitch he can't locate and hasn't graded out well in a small sample. It could happen, and I'd like to see him keep working on it, but this isn't something actionable in fantasy leagues right now and might not be this season.

Framber Valdez - Houston Astros (Slider)

Framber came off the IL two starts ago in Mexico City and appeared to bring a new slider with him. The pitch was 81.7 mph in that start, which is three mph faster than his curveball, and also has a different movement profile, so it doesn't appear to be a miscalculation by Statcast. He threw it 24 times in Mexico, with seven whiffs and a 46% CSW. Oh, boy! However, he used the slider just four times against the Mariners in his last start this weekend, so perhaps it was a pitch he wanted to use in the high altitude in Mexico City but doesn't plan to use often in his regular repertoire.

But should he?

Coming into the season, my concerns about Valdez were that he had a slightly above-average swinging strike rate and below-average CSW and ICR. He was a primary sinkerball pitcher whose sinker got hit hard in 2023, which made me nervous about him as anything other than an SP2 in fantasy. Additionally, he changed his cutter in 2023 to be three mph harder and it resulted in more swinging strikes, but it also got hit harder. He rarely threw it to righties, which means his best strikeout pitch is rarely used against the majority of hitters he faces. That put an awful lot of pressure on his curve and made me not confident in his whole arsenal.

Well, in 2024, Valdez simply stopped throwing his cutter. So he had a pitch that posted a 27% ICR and 18% SwStr% and made it harder and tighter and watched it get hit harder and instead of going back to that old version of the pitch, he just cut it out of his arsenal entirely. Um, OK.

Now you may say, "Is this new slider kind of like that old cutter?" My answer is: "I mean, kind of". Brooks Baseball doesn't even have Framber Valdez as throwing a cutter in 2022 but suggests he added one in 2023. Now, I trust Statcast more in their classification because they go by what the pitcher says he's throwing, but it's worth noting that the movement profile on the cutter in 2022 was more slider-ish.

The effective cutter was 83 mph with 4.2 inches of horizontal movement, 7.3 inches of drop, a 2,680 rpm spin rate, and was thrown with 5.9 feet of extension. This new slider is 82.8 mph with 4.6 inches of horizontal movement, 8.2 inches of drop, and a 2,726 spin rate, and is thrown with 5.5 feet of extension. So far this year, he's keeping the slider low 56% of the time but mixes it around the plate both inside and outside, while he threw the cutter low 65% of the time and pounded the outside part of the plate with it since he essentially only threw it to lefties.

That inconsistent command could just be the normal variance of a pitcher learning to find comfort in a pitch. That's supported by the fact that Valdez's slider is released with 5.5 inches of extension while his sinker is 5.8 feet, the curve is 6.2 feet, and the change is 6 feet. It seems like he's cutting off the release of his slider, perhaps because he's not comfortable with it right now.

However, if he does gain that comfort, it could be a useful pitch for him. As I mentioned above, Framber used the cutter primarily against lefties, and changing the shape and movement of the pitch in 2023 hurt him. In 2022, lefties slashed .192/.274/.231 with a 24.5% strikeout rate. He went for more strikeouts in 2023 and got them with a 31.7% strikeout rate to lefties, but he also allowed a .220/.309/.398 last line. So far in 2024, lefties are hitting .333/.467/.417 off of him, albeit across just 15 total batters.

His issues this year have also extended to right-handed hitters, and a big reason for that has been the changeup taking a rather large step backward. However, we're dealing with a small sample size and an injury, so I want to focus primarily on him fixing the minor regression we saw in 2023. I believe this slider could help with that if he can essentially make it the cutter he abandoned in 2022.

VERDICT: POTENTIALLY IMPACTFUL. I want this to be the 2022 cutter. It could really be the 2022 cutter; however, why would we be seeing command/location issues if Framber was just bringing back a pitch he threw two years ago? Why did he change it in the first place? I have so many questions. I think he'll need to make additional improvements, like fixing his changeup, but if he can start using the slider in similar ways to the way he used the cutter in 2022, I would be far more confident that Valdez will settle in as a top tier SP2 the rest of the way and flirts with fringe SP1 value.