Willi Castro is Flailing Against Left-Handed Pitching, Hampering Twins Lineup

[Peter Labuza]

Switch-hitter Willi Castro won an All-Star spot in the first half by smashing both lefties and righties. Now, he suddenly can't buy a hit against a southpaw. 

Image courtesy of © Jesse Johnson-USA TODAY Sports

On Monday night against the Royals, Willi Castro had another signature moment in his impressive, burgeoning career. Down by a run, Castro launched a homer off right-hander Brady Singer, giving the Twins a two-run lead and pushing the team on toward an 8-3 win. In Wednesday’s loss, Castro fared less well, with two strikeouts and an extremely soft line out to lefty Cole Ragans.

An 0-for-3 day against one of the best starters in the game (plus a popout against reliever Lucas Erceg) would usually be nothing to worry about. However, the bad day fits into an alarming trend for Castro since the end of June. He became an All-Star, in part, due to his switch-hitting prowess--especially his ability to punish left-handed pitching. But since the start of July, he has become an automatic out for southpaws.

The numbers should be ringing alarms within the Twins front office. Castro dropped from a stellar 202 WRC+ against left-handed pitching in the first half to a mind-bogglingly low -49 WRC+. He is 2-for-38, with only two walks and 10 strikeouts. I cannot emphasize this enough: From the beginning of the season through June, Castro was the best hitter against left-handed pitching on the team. Now, he sits dead last. Lefty pitching usually means small sample sizes, but it is quite impossible to look at these numbers and not see someone who has lost themselves at the plate.

Month	BA Against RHP	xBA Against RHP	BA Against LHP	xBA Against LHP
Mar/Apr	.197	.225	.345	.259
May	.250	.266	.417	.276
June	.274	.255	.360	.291
July	.250	.221	.080	.208
August	.355	.341	.000	.107

Castro’s usefulness to the Twins remains substantial. He fills multiple shoes throughout the defense, and plays practically every day. Crucially, during this disastrous period, he still holds a more-than-healthy 120 wRC+ against right-handed pitching. But if the team’s health improves, it will be hard to imagine a role for him with a lefty on the mound; he could be relegated to platoon duty.

What is behind this brutal drop? Simply put, lefty pitchers are finding out where to put fastballs against him. Castro has yet to hit a single fastball by a left-handed pitcher for a hit, and you can see here that they’ve finally found his weak spot from the right side of the plate, where Castro is letting balls go by and putting himself in weak counts. That often means he forces himself into swinging at anything coming by, in the hope of finding contact.

Although it looks much more red all over in his early months, what the data is showing is how Castro had no particular spot that he would hold back. Now it’s clear what to do as a southpaw: start on the outside part of the plate and get him quickly into pitcher-friendly counts.

This remains a fascinating wrinkle in Castro’s game. After all, the reason Castro has been a recipient of a staggering number of Hit-By-Pitches is because of right-handed pitchers trying to play him inside. But comparatively, left-handed pitchers are working him away, where he gets overeager. His whiff rate against lefties is just a hair under 50%, meaning half the time he swings, he just flat-out misses the ball. Left-handed pitchers are simply putting the ball on the outside edge, where he cannot seem to find it. Castro's best spots are more inside the plate; he finds himself reaching out for balls on the outside and making weak contact.

One theory was floated by broadcaster Cory Provus during a game this week. Provus reminded viewers that Castro originally had a poor start to the season, but as he moved around to each position, he quickly found his swing. Since the beginning of July, Castro has almost entirely been relegated to the infield (despite the needs in the outfield), and since Brooks Lee’s injury, he's remained at shortstop. It would be hard to believe this kind of change in defensive responsibilities could make a difference, especially when Castro remains an essential hitter against right-handed pitching, but perhaps the repetitive motion of throwing strongly with his right side across his body over to first base is adding a strain. Or, perhaps more conspiratorially, Castro is nursing an injury unbeknownst to the clubhouse that has affected his right side.

Let's assume, for a moment, that he's healthy. That certainly doesn't preclude the rest of Provus's theory. One very difficult thing about being a switch-hitter is that one must maintain two different swings, which can be exhausting and extra difficult. Paradoxically, though, you're two different hitters, but you're still only one person. A change from nomadic defensive responsibilities to playing the same place every day means changing one's mindset to half of one's job, and it's plausible that that would lead a switch-hitter into some trouble with the highly plastic task of maintaining two distinct offensive approaches.

Hurt or healthy, what is notable is how controlled Castro's recent swings are--but not always in a good way. When batting as a lefty, Castro can look a bit all over the place, leaning in and out from the plate and losing his balance in the process. But look at this pitch against Cubs reliever Drew Smyly on an 0-2 count, in an area where Castro once punished the ball:

The swing seems almost casual, and the lack of power is quite obvious. Look at how his hands seem to drop immediately after making contact. It is, simply put, not a Big Swing. Look at a recent left-handed swing where Castro finds a hanging cutter and see the difference:  You can see the power on display. The whole body leans into the swing. Something different is happening when Castro swings from the right.

Castro’s days as a starter against southpaws feel numbered, if things do not turn around. While Rocco Baldelli has kept him hitting first against right-handed pitching, he found himself in the six-hole against Ragans Wednesday. If Correa returns soon, I might imagine him dropping down even below catchers Ryan Jeffers and Christian Vázquez. Nobody wants to see it, but moves might become necessary faster than expected.

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What do you think is behind Castro’s plummeting numbers? Sound off in the comments.

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[LambchoP]

Castro is fun to watch, a nice defensive guy to have, and is having a career year offensively. That said, he shouldn't have been an all-star and we shouldn't be surprised by his streaky hitting. I think he's a good, quick leadoff guy who can steal bases, hit for ok average and occasionally put one in the seats. A decent spark plug at best, but should never be relyed upon to carry the offense in any way. Bottom line, we NEED Correa and Buxton back. So frustrating to see those guys always missing the most important games, year after year. I seriously wonder how much less injuries there would be to start players if their salary was tied to amount of games played lol?

[bean5302]

It's a game of cat and mouse. Lefties are pitching him different, and Castro will need to adjust. When Castro adjusts to the new game plan by lefties, they'll look for yet the next game plan trying to find a weakness. That's how scouting and analytics works these days.

Castro's sample size has gotten fairly big at this point. In 521 career PA vs. lefties, he owns a .700 OPS and a wRC+ 95. Considering his defensive versatility and value, he's going to continue to play every day.

[LA Vikes Fan]

Thanks for this, I think a big part of the issue might be that Castro is very tired and needs a break. He is playing more than anyone on the team, primarily because we don't have another SS with Correa and Lee both out. Can Farmer still actually play SS? I mean, that is the reason he was re-signed and made the team. 

To me, there is a pretty obvious adjustment to be made if Farmer can play SS. Castro plays SS against RH pitching with Famer there against LH starters like tonight until Correa comes back.  Gives Castro some badly needed rest and improves our bench versatility in late innings. Farmer is hitting better since he came back off the IL - .222/.333/.566 (.899) since he came back on 8/9. Most of that is against LH pitching. Miniscule sample size but still somewhat encouraging and a whole lot better than Willi has been doing. If Farmer can't do it, how about Martin at SS with Farmer at 2B? He was a SS for a long time in the Minors.

To me, the better move would be to pick up Ahmed Rosario on waivers and plug him in at SS with this 2024 .305/.331/.415 slash line. Not the best defender but better that Castro. Alas, I don't think that's going to happen . . .

[Craig Arko]

Welcome to statistical variation. 

[Road trip]

Over the course of his career (which is now a pretty good sample size), Castro is roughly an equal hitter vs right and left handed pitching (.707 vs .701 OPS).  This is actually a good thing, especially for a utility player.  Currently he's struggling a bit against lefties, but 38 at bats is a blip in a career that already has totaled nearly 1800.  He'll make adjustments, and will likely continue to be at least the hitter he has been in the past.  He might even continue to improve a bit.

[ashbury]

1 hour ago, Craig Arko said:

Welcome to statistical variation. 

Concur.  Willi didn't just show up on planet Earth this year.  He had over 500 plate appearances against lefties before this stretch of 38 PA, with an OPS above .700.  The lefties across the majors since 2019 were mystified how to reduce this bum to tears, until they all had a meeting a couple of months ago and finally figured it out?

If you look at just the one player, you may think you've discovered an insight. But if you slice and dice the stats for every player in the majors, you'll come across 38-PA oddities all over the place

Lord knows I'm not a Manuel Margot woofer, but this business about his inability to get a base hit as a pinch hitter is a similar construct. Nothing else about his 2024 suggests a lack of clutch-y-ness - his OPS with bases empty is actually just slightly worse than his OPS with men on base, etc.  Early in his career he was fine in a pinch-hitting role, so it's not plausible he's suffering from nerves now.  He's just suffering from slice-and-dice-itis.

I'm not saying slicing and dicing is bad. It can be how problems get identified.  The charts in this article are interesting, but baseball is a cat-and-mouse game at all times, and this looks to me like something that will get corrected in the normal course of events anyway.  I don't think Willi Castro is dumb.

[USAFChief]

14 minutes ago, ashbury said:

Concur.  Willi didn't just show up on planet Earth this year.  He had over 500 plate appearances against lefties before this stretch of 38 PA, with an OPS above .700.  The lefties across the majors since 2019 were mystified how to reduce this bum to tears, until they all had a meeting a couple of months ago and finally figured it out?

If you look at just the one player, you may think you've discovered an insight. But if you slice and dice the stats for every player in the majors, you'll come across 38-PA oddities all over the place

Lord knows I'm not a Manuel Margot woofer, but this business about his inability to get a base hit as a pinch hitter is a similar construct. Nothing else about his 2024 suggests a lack of clutch-y-ness - his OPS with bases empty is actually just slightly worse than his OPS with men on base, etc.  Early in his career he was fine in a pinch-hitting role, so it's not plausible he's suffering from nerves now.  He's just suffering from slice-and-dice-itis.

I'm not saying slicing and dicing is bad. It can be how problems get identified.  The charts in this article are interesting, but baseball is a cat-and-mouse game at all times, and this looks to me like something that will get corrected in the normal course of events anyway.  I don't think Willi Castro is dumb.

A statnerd truism I've always agreed with:

"Anybody can hit anything in 40 at bats."

[ashbury]

43 minutes ago, USAFChief said:

A statnerd truism I've always agreed with:

"Anybody can hit anything in 40 at bats."

I don't know if I'd even go that far. There's probably an upper limit on how good a truly bad hitter not nicknamed Hurricane can be in 40 at bats. But I agree there is practically no lower limit to how bad a good hitter can be during that stretch.

[LonelyseatinMOA]

2 hours ago, LambchoP said:

Castro is fun to watch, a nice defensive guy to have, and is having a career year offensively. That said, he shouldn't have been an all-star and we shouldn't be surprised by his streaky hitting. I think he's a good, quick leadoff guy who can steal bases, hit for ok average and occasionally put one in the seats. A decent spark plug at best, but should never be relyed upon to carry the offense in any way. Bottom line, we NEED Correa and Buxton back. So frustrating to see those guys always missing the most important games, year after year. I seriously wonder how much less injuries there would be to start players if their salary was tied to amount of games played lol?

Him having a career year offensively absolutely means he should have been an all-star, what are you talking about? 

[Jocko87]

I don't discount that being stuck to a position as a factor but I think missing the guy he's covering for is probably a bigger one.  Missing Correa and the right handed lineup not performing as well lately exposes him more than they would like with a player struggling.  

If all the righties are available he can hide out in the 7-8 spot and feast on a pitcher looking for a breather after facing Lewis, Correa, Buxton and Miranda.  

He's leading off a lot lately after being down in the order most of the first half. 

[Fatbat]

Castro must have read this thread because it didn’t age well at all.