It’s been a fun couple of weeks seeing all the work that has been done as a result of Statcast’s expanding into bat tracking. The great thing about this game is that there is always more to learn. With the addition of bat speed and swing length, we now have a better idea of telling the story of a player’s swing, but there is still so much more to tap into.

Back when I was using a Blast Motion bat sensor on a daily basis, I was exposed to every component of the swing that you could think of. Bat speed was one of them, but that only scratched the surface. There were pieces explaining my path at different points in the swing, how long it took my barrel to meet the plane of the ball, where in space that happened, and so much more. For a while, the public data available was focused on the outcome. What was the pitch? What was the result? What was the exit velocity and/or launch angle? With this new update, we’re progressing toward the how. How fast did the player swing? How long was their swing? We can now tie that in with the result, but there are additional details needed to understand the full scope of how results happened. That’ll be the focus of this piece.

First, it’s important to highlight the great work that has already been done explaining the new data we have and what the information tells (and doesn’t tell) us about the swing. Ben Clemens explained some applications of the new metrics and what their relationship with performance is on a macro scale. One thing Ben mentioned that resonated with me is thinking about the new (and old) information as inputs for us to use to understand performance rather than the answers themselves. Each piece works together to tell a story, whether that be league wide or player specific. Basically, these are pieces of information that need additional context.

Relatedly, Patrick Dubuque and Stephen Sutton-Brown from Baseball Prospectus, provided a great analysis of how to put bat speed into the context of pitch counts, from the perspective of both the hitter and pitcher. And there is more beyond just these two, including Noah Woodward’s Substack post about bat speed, swing length, and understanding what they mean and how they contribute to the swing.

Woodward touched on a few components of the swing that I’ve talked about in previous work that we still don’t have comprehensive data on from Statcast: contact point and attack angle. Swing variability, swing adjustability, having A and B swings, etc. are all extremely important to being successful at the big league level. If you have a hole in your swing, generally speaking, pitchers will expose you, so having multiple high-quality swings is going to set you up to have consistent success, just ask Triston Casas. Swing-by-swing data on attack angle, vertical and horizontal bat angle, and point of contact will all help the public understanding of swing variability, or when and how the swing changes in general.

Let’s start with attack angle. This is the angle of the bat path at contact, relative to the ground. As your bat travels through the zone, it creates a trajectory. To optimize your chances of hitting the ball in the air, the bat should be on an upward trajectory at contact, meaning you should have a positive attack angle. One component of swing variability is creating a positive attack angle at different heights, widths, and depths. You pretty much just want to be able to manipulate your barrel to move upward no matter where the pitch is. To get a better idea of what attack angle looks like, let’s look at a video from David Adler outlining a swing from Oneil Cruz:

Bat path tracking — Oneil Cruz 120.4 mph single (hardest-hit ball in MLB this year)

84.5 mph bat speed (75+ mph is the "fast swing" threshold) pic.twitter.com/FO9gA6fqva

— David Adler (@_dadler) May 21, 2024

While attack angle is officially measured as the angle of the path at contact, seeing the path leading up to contact can tell us what kind of depth the hitter creates. In this clip, the angle of the path changes as it moves from behind Cruz’s body to in front of it. This illuminates how attack angle is dependent on point of contact. In general, the farther in front of the plate your bat is, the easier it is to create a positive attack angle. However, this thread from Driveline’s Director of Hitting, Tanner Stokey, discusses the importance of creating bat speed deep in the zone. The best hitters create their peak speeds in tight windows. Like all facets of baseball, swinging is about striking a balance of creating high levels of bat speed and positive attack angles. You don’t want to have a one dimensional swing that is focused on high bat speed while ignoring the need to create ideal bat angles both deep in the zone and in front of the plate.

Depending on how you start your swing and enter the zone, it takes time to turn your barrel over into an upward slope. For many hitters, the bat needs to travel a greater distance to create the positive attack angle that leads to optimal contact. This, of course, takes more time. But, as Robert Orr pointed out last week in his piece on the relationship between pulled fly balls and swing length, a long swing isn’t necessarily a bad thing; it’s really just another data point. With access to attack angle, we could better tell the story of how a hitter like Isaac Paredes creates depth in his swing while often making ideal contact far out in front of the plate, versus a hitter who makes contact out in front without creating the necessary depth in their swing to avoid major holes.

At the same time, it’s still possible to create a positive attack angle deeper in the hitting zone. To get there, you need to make movements that aren’t easy to do while generating bat speed and controlling your body. Some hitters with great mobility use lateral torso bend — they lean toward their back leg right before contact — to get their barrel on an upward slope deep in the hitting zone. Think of Shohei Ohtani or Edouard Julien:

These two have unorthodox skills that allow them to launch pitches high in the air to the opposite field. With point of contact and attack angle, we’d be able to quantify how different they really are from their peers on top of the visual analysis.

Then there are hitters who create flatter (but still positive) attack angles with a path that stays on a similar plane throughout their swing. They get on plane with the ball early and don’t do much to change their path throughout the swing. It’s nearly impossible to do this with a steep swing. Juan Soto is a great example of this, even if he is more powerful than the other hitters with this swing style. Here is a great angle that illustrates what I’m referencing:

Bat path tracking — Juan Soto 112.0 mph line-drive single off Justin Verlander

Staying on top of a hanging curveball at the top of the zone pic.twitter.com/IRhdzHVMy8

— David Adler (@_dadler) May 8, 2024

Soto’s vertical entry angle (angle of the bat relative to the ground at the beginning of the downswing) isn’t far off from his attack angle. You can see how much this swing contrasts with that of Cruz, who is a big dude with a narrow stance. Because of that, his bat path is vertically oriented, and his bat needs to travel a greater distance to get on plane with the ball. With more detailed information of barrel angles at different points in the swing, we would know more about how hitters like Soto and Cruz vary from one another when it comes to getting and staying on plane.

This has been a ton of information all at once, so I’ll leave you with one last tidbit. Depending on the hitter, the angle of the path at contact can be very different from the angle of the barrel at contact (relative to the ground), known as vertical bat angle. While I’ve cited average vertical bat angle from SwingGraphs on several occasions, I’ve always focused on putting the metric into context because it varies based on several factors. Luis Arraez and Aaron Judge can have similar average vertical bat angles, but that doesn’t tell us anything about how different their swings are. We know the metric depends on pitch height, but even that alone isn’t enough to explain why Judge is a launcher and Arraez is a sprayer. As we learned earlier, each data point is an input and isn’t meant to be used alone.

There is no question teams have been using, monitoring, and applying these data to scout and develop players for years now, but despite all the metrics that we have, the information on the public side is still lagging. Ideally, in future years, we will gain access to more swing data so that we can better understand the game we love.

First base defense is complicated. It isn’t one of the most difficult positions, but that doesn’t mean it doesn’t have its own challenges. Players in the latter half of their careers who have lost athleticism sometimes adopt the position as their new home, which is interesting because it is much more difficult to learn a new position when you’re past your athletic prime. But because first base doesn’t require top tier athleticism, it’s not uncommon for that to happen. Bryce Harper’s case is a perfect example of this.

Between Philadelphia’s crowded outfield and its interest in keeping its star healthy as he ages through his 30s, first base became a viable option for the former MVP when the position opened up and he was returning from Tommy John surgery in record time. Last year, he handled it well — even if he at times ventured too far off the bag for grounders in the hole, as if he were back in right field trying to cut the ball off in the gap — given that he was learning the position on the fly.

It was a bet on Harper’s baseball skills and IQ that seems to have worked out well. His defensive metrics looked solid in 2023 (+3 OAA); of course, considering the small sample, we shouldn’t take these numbers as bond, but they were encouraging nonetheless. Now, with a full offseason of learning the position and a month’s worth of plays, we have a better idea of what his true talent is at the position. Later in this article, we’ll watch some video of Harper playing first to evaluate where he stands. But first, let’s take a look at the numbers.

So far in his first base career, Harper has a +6 OAA and a Success Rate Added between three and four percent. His OAA this season is +3, which is the highest among first basemen. Basically, the numbers indicated that Harper had a solid foundation already, and with more experience, he’s become one of the top defenders at his position.

For the rest of this piece, we’ll use video to break down Harper’s handling of three fundamental facets of the position: his footwork on groundballs that he takes unassisted, his feeds and feel for flipping to pitchers, and his opportunities to make outs at second. There are other aspects that go into first base defense — such as catching pickoff attempts, securing scoops, and receiving cutoffs before delivering relays — but I’m most interested in his skills fielding groundballs. With that said, let’s start by looking at grounders hit close enough to the bag for Harper to make an unassisted putout:

Unassisted Groundballs

Two things stick out to me right away: Harper is good at working from the ground up, and he almost always keeps his body moving in the right direction. Any shortstop would tell you that progressively moving your feet and body weight toward your target as you field the ball is crucial. The same premise holds for first baseman.

With a slow chopper, you have to stagger your feet to make sure you stay under control and don’t overplay the baseball and get a bad hop. When working toward the first base line, as Harper has done so well, you balance how hard the ball was hit with the angle you take to it; on harder hit balls, you put your body on the line to protect against a double, whereas when a deep chopper comes, you reorient your center of mass toward the bag to make sure you’re ready for a race with the runner or to throw to the pitcher. Harper looks very comfortable making these decisions. I snuck the liner from Matt Olson in there to show how quick he can be on his feet. Not every first baseman can move like that. Now, let’s move on to a more complicated task: flipping to the pitcher.

Flips to Pitcher

Harper has done well sticking to the fundamentals here. He has a rhythm established with Zack Wheeler in particular, but his execution of leading each pitcher to the bag is on point. He maintains composure throughout each of the throws, even when the batter-runner is a speedster like Elly De La Cruz. Urgency and pace are important aspects of fielding grounders at first because you can get caught in a foot race with a runner. But if you’re consistent with your delivery and have a good feel for speeding up your arm when necessary, there is no need to rush your feet.

I’m impressed by Harper’s ability to make plays moving to his right. He uses his right foot to plant or pivot very well. That has a lot to do with his athleticism. He gets into good positions to stay under the baseball and make reads with his hands. The next clips highlight that even more:

Potential Plays to Second

There are three different moves that you can make as a right-handed thrower when deciding to deliver a fire to second from the various first base positions (shallow, medium, deep) — you can pivot toward your throwing shoulder to square your body to the bag, you can spin toward your forehand and non-throwing shoulder to square your body, or you can make the throw on the run. Harper clearly has a feel those three moves.

On the grounder hit by Olson, Harper’s footwork is fantastic as he spins, turns, and throws, and his delivery is to the correct side of second base. Then on a similar grounder (the third play), he realizes he doesn’t have a throwing lane and decides to take the sure out at first. On the hard groundball from Mike Trout, Harper switches his feet very quickly (like a catcher would) and delivers the ball right on top of the bag. The only hiccup comes in the final play in the clip, when he gets the groundball near the outfield and decides to hold it instead of making a spinning throw to second. If he fires to second instead, the Phillies have had a shot at an inning-ending double play. This is something to keep your eyes on as Harper continues to develop at the position. It’s the longest throw a first baseman will make and requires a quick decision. He’s clearly comfortable making the spinning throw from a shallow depth, but this last piece will help him become more complete at the position.

In general, I’m impressed with how comfortable the Phillies slugger looks at his new position. His fundamentals are on point. He can pop off the bag quickly after holding a runner on and get his feet in check to move in any direction. Even when he makes a mistake, it’s not because he isn’t prepared with his feet. This might not be a Mookie Betts-level position switch, but it’s still worth appreciating.

CJ Abrams has that look this year. After showing a glimpse of his offensive potential in 2023, his skills are on full display to start the season. Abrams’ projectable frame always seemed like it could facilitate him adding power. Whether he ever got to that power was dependent on his swing mechanics.

Up until this year, the lefty had a steep, pushy entry into the hitting zone. That resulted in a suboptimal launch angle distribution. In 2023, he had a 32.6% sweet-spot rate, which was in the 30th percentile. (A player’s sweet spot percentage is defined as the percentage of their batted balls hit between eight and 32 degrees.) So instead of hitting balls at launch angles that would result in line drives and hard-hit fly balls, Abrams hit a ton of popups and groundballs. His swing had a limited range of quality contact points.

He may have swatted 18 home runs, but those long balls were mixed in with consistent mishits. When you swing down into the hitting zone like Abrams did last year, it can lead you to be what a lot of hitting coaches call a collision hitter. If your bat path doesn’t have much room for error, you might still run into some homers from time to time, but there is only a tight window for you to do so. Rather than your barrel moving up through the entire hitting zone, it only does so at one point in space. That might be hard to conceptualize, so let’s check out some video of Abrams last year, focusing primarily on how his hands descend when he starts his swing. Read the rest of this entry »

Anthony Volpe had a rough rookie season at the plate. He hit just .209/.282/.383, which amounted to an 84 wRC+ despite his 21 home runs. Neither his mechanics nor swing decisions looked viable. A swing tailored to consistently lifting the ball propelled his minor league success, but it was also a key reason why he struggled in 2023. He never showed the requisite discipline or contact skills on low and away breaking balls to rely on this swing style, and he failed to make up for that deficiency with plus performance in other parts of the zone.

Volpe’s .142 wOBA against same-handed breaking balls low and away was among the worst in the game. A big part of adapting to major league pitching is proving you can perform against breaking balls. Volpe never did that, so pitchers spammed him with them. Out of the 267 hitters who saw at least 1,250 pitches in 2023, he saw the 22nd-highest breaking ball percentage. He got the classic rookie treatment and couldn’t handle it. So instead of trying to make his existing swing work, he flattened out his bat path with the hope of creating strengths in other areas of the zone while mitigating his big weakness.

I’m going to offer my own video analysis here, but there already has been a lot of great work done on Volpe’s swing change. The Athletic’s Chris Kirschner spoke with Volpe during spring training about how and why flattening his swing path was an offseason priority. Daniel R. Epstein of Baseball Prospectus just provided an analysis on the swing decision part of this and how it has paired with improved contact. Volpe’s adjustments have resulted in an increase of 11 percentage points in Z-Contact%, and he has chased and whiffed significantly less often as well. Entering play Wednesday, he is batting .349/.438/.508 with a 183 wRC+ in 74 plate appearances. And while it is early and small sample caveats apply, his adjustments, as I’ll detail below, are fueling a hot start that has the juice for a real breakout.

Volpe is already showing his new swing and mindset can handle breaking balls; he has a .345 xwOBA against them, and his chase rate against them (15.7%) has decreased by over 14 percentage points compared to 2023. Given his immense struggles last season, just laying off the pitch more often would do him wonders. On top of that, having a flatter entry into the zone makes it more difficult to get to same-handed breaking balls low and away, making it even more important he lay off the pitch as much as he can. He’s off to a good start as far as that’s concerned.

This spring, Volpe told Kirschner, “… if I can still be late and shoot the ball to right field or when I’m early and out in front, still have enough to do something with the pitch, that’s the goal.” Flattening your bat path isn’t the answer for everybody, but if it helps you create more depth (positive bat angle at different depths in the hitting zone) in your points of contact relative to your previous swing, then you can create more room for error because your barrel is on plane for a longer period of time. Here’s how it works for Volpe: Against high heat, he can still be on plane to shoot the ball to right; against a back-foot breaker from a lefty pitcher, he can be early and still make flush contact in the air.

This approach doesn’t work as well for a hitter with a steep swing. If your bat head is pointing up, you have to turn your barrel over to point it down. The steeper your bat angle, the more you have to turn the barrel. It’s much easier to get your bat flat deep into the zone if you start with your bat relatively flat and rotate from there. It takes less time and less movement, hence there being a better chance at making contact more consistently. There is more nuance to it, but that is generally how the process goes. But remember, this doesn’t work for every hitter. Creating bat speed in deeper parts of the zone while maintaining an upward slope with your swing isn’t easy. Luckily that has always been a skill for Volpe.

In the shortstop’s prospect report, Eric Longenhagen said, “His swing is like a right-handed version of Juan Soto’s, capable of getting underneath the baseball in basically every part of the zone, in part because of the flexibility and athleticism in his lower half.” Soto has one of the flattest swings in baseball, but he can still elevate a variety of pitches because of the combination of his torso bend and lower-half maneuverability. In layman’s terms, he can rely on body adjustments to do the work of creating lift while keeping his bat flatter through the zone than most hitters can. Volpe can do the same: The lift will happen even with his flatter swing because he can combine body adjustments with a barrel that is on plane through most of the hitting zone.

Eric also pointed out that Volpe worked with a private instructor to re-engineer his swing before his prospect breakout. That is not an exaggeration. Volpe literally made his swing in a hitting lab with the help of biomechanical data. That process is probably a big reason why over this offseason he was able to remake his swing again, this time to flatten out his entry into the zone while maintaining the key strength of his swing: lower half maneuverability. So let’s explore how Volpe did this, going step by step through it.

Setup Into Load

First thing: Volpe isn’t a big guy. He can naturally create a flat entry into the zone just with an upright stance and high hands. Even last year, it’s not as if he had an extremely steep swing, just steeper than was ideal for him. By standing more upright, he immediately sets himself up for a flatter entry because his shoulders and torso are neutral relative to the ground.

Peak Leg Kick Into Foot Plant

Volpe’s leg kick was a bit all over the place last year, but he ended up with a relatively closed stance. That complicated things for him against inner-third pitches because opening his front hip while maintaining a deep path was a strength of his. Closing out may have put more pressure on his backside to hold his stability. He went back to a neutral start this year and now looks more like he did as a prospect. As he plants his foot, he is still able to hold his posture and start his flatter entry into the zone without putting pressure on any particular part of his body to do the work.

Swing and Follow Through

The differences here may be tough to discern at first glance, but there are two things that are important to pay attention to. First, in the 2023 clip, Volpe’s back leg starts to collapse before contact. That alters his timing and path to the point that he catches the ball off the end of the bat and skies it for a fly ball out. This year, that leg is staying strong through the swing and only dips after the point of contact. That is much more stable and controlled. It’s the difference between a fly ball and a line drive over the wall.

Also notice how his front foot withstands and then transfers energy. Against Patrick Corbin in 2023, that foot peels over and eventually needs another step to the side to catch the energy transfer, whereas against Jesús Luzardo from last week, it has the initial peel but transfers back toward the midpoint of his body without needing that extra sidestep. That indicates better weight transfer. If you can make tight turns around the midpoint of your body, you’ll always be in a better position to adjust. This swing is one example of that.

Small sample aside, Volpe looks like a completely different hitter this year. This piece mostly focused on his mechanics, but he is also showing tremendous poise and conviction in his swing decisions. His swing rate in the Shadow Zone has dropped 12 percentage points. He is taking borderline pitches off the plate with no hesitation whatsoever. Combine that with a drastically improved swing process and you have what we’ve seen so far. At some point, pitchers will adjust and Volpe will need to do the same, but a more versatile swing should help him do that.

I’ve wanted to write about Daulton Varsho for a long time. As a catcher turned elite defensive outfielder, he’s had a rare career progression. Because of that, he’s been one of my favorite players to watch. But I’m not here to talk about his defense, or even his elite baserunning for that matter. Instead, the focus is going to be on his one non-elite skill: his bat.

Through 1,603 career plate appearances, Varsho has a 96 wRC+. He was a slightly above-average hitter from 2021-2022, but he took a big step back in his first year with the Blue Jays, posting an 85 wRC+ across 581 plate appearances. His peripherals were about the same as they were the previous year, but his output was significantly worse. It was confusing to see. The expectation was that he would make a leap in his third full season, and the projections supported that. ZiPS’ median projection had him pegged for a 117 OPS+; his actual production ended up being a bottom decile outcome. Despite the regression, ZiPS is still confident Varsho can be a little better than league average with the bat this season, with a projected 107 wRC+.

Any hitter who saw as big of a drop as Varsho did last year would be keen to overhaul his process, though at times it can be difficult to determine what part of the profile needs the most attention. Luckily for Varsho, his was an obvious diagnosis that had little to do with his approach; his swing decisions actually improved in 2023. Instead, the problem can be found in his bat tracking data.

Let’s quickly redefine some terms before starting the analysis. First is Vertical Entry Angle (VEA): Sourcing the definition (and data) from SwingGraphs, VEA is the vertical angle of the bat approximately 83 milliseconds before contact, or in other words, the angle of the bat relative to the ground at the start of the down swing. Then there is Vertical Bat Angle (VBA), something I’ve cited many times in previous work. VBA is the angle of the bat relative to the ground at contact. Lastly, there is Attack Angle (AA), which represents the vertical direction of the bat at contact.

Each of these measurements are important for understanding any hitter. The way they work and interact with one another can tell the story of a swing. For Varsho, the way these measurements work together is especially important because he tends to live on the extreme ends of them. Here is a table summarizing his VBA and AA relative to the league:

Varsho’s VBA is consistently one of the lowest in baseball. That means on average, his bat is flatter at the point of contact than most of the league. While it’s important to note that VBA is dependent on pitch height (VBA decreases as you move up in the zone), it’s not as if Varsho is only making contact with high pitches and that alone is the reason for his low mark. In fact, his contact heights are typically average or below average – not exactly the hitter you’d expect to have a VBA this low. Then, when it comes to AA, his mark was among the highest in 2022 and above average in 2023. Both years, he was among the leaders in positive differential between VBA and AA (AA > VBA). That is interesting, and perhaps a big red flag considering his profile as a hitter.

There is no such thing as an absolute in baseball – there is always room for departure from the norm – but it’s typically not optimal for a hitter to change the angle of his bat this much through his swing. If you hit the ball hard, you can probably make it work better than most, but Varsho doesn’t have that kind of room for error. Taking the bat off its natural plane of movement will likely result in lots of mishits. Unsurprisingly, Varsho was among the league leaders in pop-up rate in 2023. This swing profile is far from ideal, especially because he doesn’t have the power to overcome the deficiencies. Now is a good time to pivot to VEA and its role in Varsho’s swing.

I did not include VEA in the table because the number is best represented by a range, since the metric is still a work in progress at SwingGraphs and the capture rate isn’t always consistent. From September 2022 through last season, Varsho’s VEA has fluctuated between 42 and 48 degrees. That means he tends to flatten his bat from the start of the downswing through contact at a range between 16 to 21 degrees. Again, that is among the highest in baseball, if not the very highest.

Here is a quick screenshot of about where VEA is captured:

So, from the point you see above to contact (VEA to VBA), he flattens his bat angle a ton. That helps put the pieces of Varsho’s swing puzzle together. Think about it from a reciprocal movement perspective. How you set yourself up to move will directly impact the next step in the kinetic chain. If your bat is pointing upward as the downswing begins, then its natural response is to have a vertically oriented path through the ball, hence Varsho’s high VEA into high AA. By making his barrel flat at impact (despite moving it on an upward path), he’s forcing it off its natural path, which has a negative effect on his contact quality. Let’s watch a few swings from last year to remember what his swing actually looks like:

There are some swings where it goes right and others where it goes wrong. What’s clear even from this handful is that Varsho tinkered with his hand placement throughout last season, perhaps in an attempt to get comfortable through a bumpy year. When he spoke to David Laurila a few weeks ago, he discussed his mindset at the plate. After Laurila pointed out to Varsho that he pulls the ball more often than any hitter in the league and followed up by asking if Varsho wanted to lift the ball, the Jays outfielder made it clear that his thought process is to hit grounders. This stuck out to me – not because of any criticism of the old school mindset – but because of how he sets his swing up.

As I’ve pointed out, Varsho’s VEA puts him in line for a steep swing, but his intent to hit the ball on the ground plays out through his flat VBA. The flat VBA itself isn’t the issue. Plenty of other hitters have success with it. It’s that he doesn’t optimally set himself up to have a flat swing. If he started his downswing flatter, he would be in a better position to execute on the flat swing he intends to have. Cue 2024 spring training:

Well, I’m intrigued. Yeah, the results are better in the small sample, but that doesn’t really matter here. This is as sound of a process as I could have imagined for Varsho. If his goal is to have a low, line drive oriented swing, then this is how he should set up for it.
He points his bat down in his stance to remind him to keep the bat flat as he starts his swing. The open stance is probably a comfort thing, but it could help create more space for him to get his bat going deeper in the zone. That’s something easier to do with a flat bat path than a steep one. Either way, these adjustments align with his stated plan and the other components of his swing.

As of now, it’s unclear whether these changes will result in the offensive breakout we were expecting last year. We’ll need regular season data to answer that question. But what it does do is prove that Varsho is cleaning up his process and matching his mental plan to his physical mechanics. That’s important. If he can return to his league-average hitting, it’ll be enough to make him a valuable player, given his elite fielding and baserunning. If he can be better than that, he’ll emerge as one of the game’s more talented stars. For now, let’s see how April goes.

There are so many great defenders in the majors right now. In the infield, there are elite shortstops, like Francisco Lindor and Dansby Swanson. In the outfield, there are the dudes who don’t let anything drop, such as Brenton Doyle and Harrison Bader. But none of these players are projected to lead baseball in Def, according to ZiPS. That title belongs to San Francisco Giants catcher Patrick Bailey.

Last year, Bailey led all players in Def with 26.8 runs. On the Statcast side of things, he was second in Fielding Run Value with +18, behind Doyle. He is unquestionably one of the most valuable defenders in the game, and much of that is due to his elite framing. He accumulated +16 framing runs and recorded a 52.9% strike rate – both the highest marks in baseball.

If you look at the Statcast framing leaderboard, you’ll notice one color for Bailey: red. He is above average in all nine parts of the shadow zone. That is simply unheard of. Typically, for catchers to be elite in one area, they tend to sacrifice another part of the zone. Take Adley Rutschman, for example. He is elite at the top of the zone but slightly below average at the bottom. Sean Murphy has the opposite tendency. He steals at the bottom while losing some at the top. Bailey is a departure from the norm. He can steal strikes in any part of the zone without sacrificing elsewhere.

That’s an impressive skill that made Bailey stand out last season. It’s also the exact kind of statistical quirk that warrants a video deep dive to uncover how he does it. Before jumping in, let’s discuss the two things we’ll be paying attention to here: Bailey’s pre-pitch stances and glove turns. To be this efficient around the strike zone, catchers not only have to have multiple stances, but they also have to know when to use them. By understanding their pitching staff and their movement profiles, they know when to deploy what stance and how to best use their hands.

The following clips will display how Bailey switches up his approach depending on the pitcher and/or location. Let’s start with Logan Webb – the sinkerballer and command artist:

Sinker

Where Bailey sets up behind the plate dictates his stance. He favors his inside knee down most of the time, but there is some variance depending on the pitcher and pitch. More so than when he is catching other pitchers, he has no problem setting up closer to the edges of the plate for Webb.

The key difference between the two sinkers is how he uses his glove turn in preparation for the pitch. On the arm side sinker, he uses more of a straight down quarter turn. Whereas with the glove side sinker, you’ll notice a more deliberate rounded turn. As a catcher, matching the plane of the pitch leads to the smoothest reception. If you don’t alter the rotation of your glove as you catch the ball, it appears as natural as possible to the umpire, resulting in a better chance at a strike call. Bailey has a perfect understanding of this, which can also be seen when he receives sliders:

Slider

On the arm side, it’s pretty standard. The glove side is where the quarter turn sticks out. Pushing a breaking ball back toward the middle of the plate can often look forced. But if a catcher is already tracing that movement before he receives the ball, it appears natural and can lead to stolen strike calls. Additionally, Bailey’s ability to switch which leg is down lets him be as loose as possible with his movements after the pitch is released. This allows him to smoothly shift his positioning to ensure that he catches the pitch closer to the center of his body, which makes it look more like a strike to the umpire.

While the one-knee catching stance has swept through the league, it’s still not common for catchers to switch from knee to knee as often as Bailey does. It puts him in a better position to handle pitches coming in from different angles. When a catcher has his inside knee up, that leg can sometimes make it difficult for him to reach across his body. Since Bailey almost always has his inside knee down for horizontal moving pitches, that’s not a concern. But there are some situations in which Bailey will alter this approach, such as when Webb throws his changeup:

Changeup

He switched from his typical stance, with his outside knee up, when catching the changeup with the lefty-hitting Jonah Heim at the plate. Bailey is most likely more comfortable putting his right knee up when Webb throws his changeup because that pitch doesn’t get much horizontal movement, and his glove turn probably feels more natural when he has space on his glove side. However, he is forced to switch his stance when there is a runner on first and second base is vacant because he can’t make throws with his left knee down. But that isn’t an issue for him, because he is comfortable flipping his stance.

Now, let’s see how Bailey handles Camilo Doval, whose arsenal — 100 mph rising cutters, 98 mph sinkers, 90 mph sliders — is completely different than Webb’s repertoire. Bailey knows that, so he takes a slightly different approach:

There are a few things to note here. First, Bailey gets in a lower stance with the slider coming and a runner on third, which puts him in a better position to block anything in the dirt. His low glove turn also prepares him to either flip his mitt over to get into a blocking stance or quickly shift it for a backhand pick. With high velocity sliders, a pick can often be more effective than a traditional chest block because there isn’t much time for a catcher to drop to his knees and get in front of the pitch. Meanwhile, Bailey hardly moves his glove in preparation for the cutter. Doval probably needs the high target for a visual marker, and an exaggerated glove turn isn’t needed for high pitches anyways.

Watching Bailey handle all types of high pitches is one of his best skills as a framer. No matter if it’s a heater or breaker, he knows when to attack pitches and when to be more patient. Doval’s cutter is one example of that, but the way he receives high sinkers and high sweepers perfectly displays that dichotomy:

Sinkers

Sweepers

Since Bailey sets up on the edges, it’s important his glove gets to the spot where the sinkers are going before they arrive, so long as that location is within the width of his shoulders. Anything outside of his frame will clearly look like a ball to an umpire, and the whole point of framing is to be inconspicuous. So when he’s expecting a backdoor sinker from Taylor Rogers (top left), he receives the pitch in the middle of his body while slightly pointing his shoulders toward the batter, Corbin Carroll. The pitch was out of the zone but appeared right on the edge because of how Bailey presented it. On the pitch from Alex Wood (top right), Bailey knows to keep his posture high and eyes over the squared bunt. That lets him beat the pitch from going too far out of the zone while giving the umpire a clear look at it. It was a great mid-pitch adjustment that led to another strike on a borderline pitch.

His approach to sweepers is much more patient. This is a pitch that will keep moving as long as the catcher lets it. If it starts out of the zone, letting it travel as much as possible gives it a better chance to scratch the edge of the plate. Even if the pitch passes the plate out of the zone – like against Randal Grichuk (bottom left) – the catcher can let it get deep enough so that it still looks like a strike when he catches it behind the plate. This is a good time to refocus on Bailey’s stances. It’s more difficult for a catcher to let these pitches travel with his leg or knee in the way. Keeping the inside knee down lets him adjust his upper body as needed while giving his arm the space it needs to move freely. The more space for smooth movement, the better prepared he is to let the pitch get deeper into the zone.

It’s hard to consistently do what Bailey does when it comes to switching stances. Not all players have the mobility on both sides of their body. On top of that, Bailey demonstrates an advanced understanding of pitch movement and matching planes with glove turns no matter who is one the mound. It’s the full pitch framing package. With a full season of work, I’m excited to see how much defensive value Bailey can bring. We could be in store for one of the best defensive seasons in recent memory.

Among other things, we at FanGraphs are known for our projections, especially at this time of year. We like to think that’s because our projection systems are good! But it’s worth remembering that projections always include uncertainly. ZiPS, for example, reflects a range of projected outcomes based on a million simulations of the coming season, with the first percentile representing the worst projected performance and the 99th percentile, the best. The numbers you see on our player pages reflect the 50th percentile projection — the median projected outcome — for each player.

For me, the fun begins when the projections are live, because I use them as a starting point to begin my own analysis using data points that are not folded into the player projections, such as video and bat tracking information. I like using these tools because they allow me to see whether a player has a foundation in place that could help him exceed his median projection. For this piece, I want to focus on players’ potential ceilings, which I will define as their 90th percentile projection, so that we can stay within the realm of possibility. (Theoretically, a player could hit 80 home runs this season, which would surely be his peak performance, but that is so extremely unlikely to happen that it is not worth considering here.) From the model’s perspective, all players’ 90th percentile outcomes are equally likely; my analysis is more subjective. I will use additional information to reinforce confidence that a player can indeed reach his ceiling.

The goal here was to look at players who have a lot of uncertainty in their projections, due to a volatile profile, an unproven track record, or both. From there, I settled on a group of three inherently risky players who have specific traits that I think should lead to an immediate improvement. With that said, let’s get started:

I’ve presented Adolis García’s 2023 performance to provide a comparison to his 2024 projections. Going into last season, García’s 50th percentile OPS+ and WAR were 103 and 2.0, respectively, meaning that his actual production greatly exceeded his median projection. In response to this, ZiPS is more confident in García entering this season, even as his profile remains volatile.

Is it possible for him to get even more out of his bat this season? I think so. In terms of plate discipline and swing decisions, García made a significant stride forward in 2023. However, his projections expect his BB/K ratio to regress from his .37 mark last season and be closer to his 2022 level of .22. Using Robert Orr’s SEAGER metric, which calculates a combination of selectivity and strategic aggression, García scored a 19.4% last year. That was in the 88th percentile of hitters, an improvement from being slightly above average in 2022.

García slightly improved his Hittable Pitch Take%, while simultaneously increasing his Selectivity% by nearly five percentage points. Yes, that helped him draw more walks than was expected of him, but it also allowed him to crush 39 homers. García is following an intuitive path to plate discipline improvement. After posting bottom decile whiff and chase rates in 2021 and 2022, he significantly cut down on his chasing last year. Now that he has proven to possess a better understanding of the strike zone, the next step is to stop whiffing as much. His mechanics are efficient, his plate coverage is good, and he has already shown a knack for improvement. That’s a darn good recipe for a player looking to get the most out of his skills.

García’s case is a bit simpler than the two players we’ll discuss next. Let’s move onto another talented outfielder:

I’m a Riley Greene believer. My expectations for him last year were higher than where his performance fell, but he also had two unlikely injuries that could explain his underwhelming season. In May, he had a stress fracture in his fibula that caused him to miss just over a month. Then, after looking fantastic in his return, he tore his UCL in his non-throwing arm. It was a bizarre bit of luck for a player looking to prove himself as a cornerstone piece in Detroit. His projections for 2024 reflect a wide net of uncertainty in his offensive profile, but also a high ceiling because he boasts great hitting skills and is only entering his age-23 season.

Greene hits the snot out of the ball. His xwOBACON of .477 was in the top 4% of the league. His ability to manipulate his posture to get to different pitch heights allows him to have great plate coverage. His average 40.4-degree Vertical Bat Angle (VBA) – the angle of the barrel relative to the ground at impact – is among the steepest in the majors, and he combines it with a path that always works up and through the baseball. As a result, he has an ideal launch-angle distribution and consistently flush batted-ball spin. Here are a few videos of him covering pitches all over the strike zone:

Velocity up? Check. Slow and away? Check. Back foot breaker? Check. His swing is so versatile because of how he changes his torso tilt while still maintaining upward angles on his swings. He is capable of getting to just about anything, which is why he was so good against breaking balls on the season, with with a .366 xwOBA against them that ranked 18th among 260 hitters who saw at least 400 such pitches in 2023. His proficient barrel and body variabilities are the exact skills I’m looking for when betting on a player to hit his ceiling, especially if the hitter impacts the ball like Greene does. With health and better controlled aggression, Greene will put himself in a great position to hit his 90th percentile outcome. A 151 OPS+ would be a major step up from the 117 he posted last year, but at times, he has already flashed that level of dominance. The final piece of the puzzle is consistency.

Now, let’s evaluate an exciting young catcher looking to prove his 2023 season was no fluke:

Bo Naylor hit his tail off last year to the tune of a 124 wRC+. In a Guardians lineup that didn’t have much beyond José Ramírez and older brother Josh Naylor, Bo emerged as one of the team’s top offensive contributors from the moment he cemented himself as the primary catcher. His great performance, albeit in limited time, is reflected in his ceiling, while his floor is based on his lack of a track record in the majors.

It’s a good sign whenever a young catcher has such a solid 50th percentile projection, though in Naylor’s case, the expectation is that his power will drop off. That is reasonable when you consider his .232 ISO last year would’ve been third among catchers with at least 300 plate appearances, despite the fact that his 30.8% hard-hit rate would’ve ranked 235th among the 258 qualified hitters, according to Baseball Savant. On top of that, Naylor outpaced his expected statistics by quite a wide margin. His .347 wOBA was considerably higher than his .309 xwOBA and his .379 xSLG was far off from his .470 mark. But wait a minute — we know that there is sometimes more to uncover when we see discrepancies like this. Is Naylor one of those cases?

Of the 406 players last year who had at least 100 batted balls, Naylor ranked 18th in Pulled FB% (sourced from Orr’s leaderboards again). If Naylor is one of the better players in the game at pulling fly balls consistently, then he should be able to outperform his expected statistics again in 2024. Does he have the swing mechanics and path to keep up this pace? Naylor, a left-handed batter, is typically hitting with the platoon advantage, making it easier for him to create the Horizontal Bat Angles (HBA) required to pull these pitches consistently. Matchups with righty pitchers are ideal for lefty hitters with pulled fly ball approaches. Here are a few clips that show him executing that swing on different pitches:

Naylor is going to be challenged to hit pitches away from his body to the pull side, but if he can keep that front side locked like he did in these swings, he may be able to keep up his pull side success despite the lack of raw power. In these swings, he showed that he can turn on 99 mph heat, but also that he can stay disciplined enough to wait on an 88 mph changeup. Given what we know about his patience and plate discipline, Naylor is the type of player who should be able to match his swing decisions with his swing strengths. That’s an important skill that could help him build upon his impressive debut.

With spring training games in full swing, the pressure is mounting for baseball’s remaining free agents to find homes. After all, nobody wants to miss out on the weather in Florida or Arizona this time of year, and Opening Day is just a few weeks away. Now Tim Anderson won’t have to fret. Anderson is heading to the Miami Marlins on a one-year, $5 million deal. With a clear path to the starting shortstop role, the 30-year-old will no doubt hope to re-enter free agency this winter having bounced back from his disappointing final season in Chicago.

Anderson’s fit in Miami is an interesting one. If he can stay healthy and return to his prior form, he could help to stabilize the shortstop position in Miami. But he also constitutes a risky addition to an already uncertain Marlins lineup. It’s not hard to imagine a scenario where neither Anderson nor Jazz Chisholm Jr. has an offensive bounce-back, Luis Arraez regresses, and Jake Burger’s contact overhaul proves to be just a flash in the pan; it could all go sideways pretty quickly. But if it goes right, this could be an exciting lineup. If nothing else, the top three of Arraez, Anderson, and Chisholm make for a very fun group. Still, in order for things to go right for Anderson, he needs to recover some of the BABIP skills that were a key reason for his success. Let’s focus on how exactly that might happen.

From 2019-2022, Anderson led the majors in batting average with a .318 mark. On a hit per plate appearance basis, nobody was more productive. Then in 2023, he cratered. Knee, shoulder, forearm, and neck injuries all contributed to the contact hitter dropping to a 60 wRC+ and -0.5 WAR in 123 games. Add to that concerns about his ability to stick at shortstop, and you have yourself a player who fell $3 million short of his median crowdsourced contract prediction. The shape of Anderson’s production through his successful four-year run was inherently volatile. He definitely possessed skills that propelled him to run above-average BABIPs, but the margin for error for that hitting style is razor thin; a handful of injuries and some loss of strength can make an otherwise productive profile almost unplayable. Read the rest of this entry »

There is no baseball topic that gets me more excited than swing diversity. A player’s swing is like a fingerprint: No two are the same. But even similar swings can yield extremely different results. There are many ways to compare swings, but because Vertical Bat Angle (VBA), the angle of the bat at contact relative to the ground, is the most accessible (thanks, SwingGraphs), it’s been my go-to proxy for the last year or so. Of course, you can always use your eyes to visually analyze swings, but having the data to confirm it helps inform the evaluation.

Lately, my video evaluations have focused on hitters with steep VBAs, and even among this group there is a ton of swing diversity. Some take golf-like swings to get to their steep planes and others employ one of my favorite styles: the chicken-wing swing.

Intuitively, it makes sense that hitters with steeps paths are more prone to whiffs than those who have flatter swings. Even so, some of the game’s best contact hitters have swings as steep as some of those who are the most whiff prone. Luis Arraez, for example, has a swing that is just as steep as J.D. Martinez’s, at least according to VBA. Without the data to confirm, it’s hard to know if the same holds true for Attack Angle (AA), the angle of the bat’s path at impact.

To show you exactly what I mean, I’ll compare pairs of hitters with nearly identical average VBAs, but different offensive profiles. A few weeks ago, Davy Andrews wrote about Edouard Julien and the bizarre nature of his platoon splits (and a tune to go along with it). His entire offensive profile drastically changes depending on if he’s facing a lefty or righty. It’s fascinating. After I read the piece, I was immediately curious as to how those trends might relate to Julien’s swing path. At 40 degrees, Julien has one of the steepest VBAs in the majors. It’s almost a perfect diagonal. Here are a few slow motion swings that showcase that:

No matter how high or low the pitch is, Julien manages to get his bat on a diagonal, which last year helped him run an xwOBACON of .443, well above average. His diagonal angle also allows him to crush fastballs. He had a .408 wOBA against heaters but struggled mightily (.287 wOBA) vs. breaking balls. Production against different pitch types is where you tend to see some deviation between hitters with similar VBAs. Like Julien, Freddie Freeman is also a lefty batter with a steep VBA (41.7 degrees), yet despite their similar angles, Julien ran a 44.3% whiff rate against breaking pitches, while Freeman’s whiff rate vs. breaking balls was 27.7%. There are swing components other than VBA that contribute to how such divergence can happen. But before getting to that, let’s check out some of Freeman’s swings from 2023:

Man, Freeman is smooth. Because both he and Julien set up with high hands, they can create a steep path at different pitch heights. This setup allows them to drop their barrel easily and rely on changing posture to adjust to locations. How they do it, though, is where their swings differ. Julien uses more aggressive movements to get to different pitch heights, while Freeman shifts his shoulder plane and avoids more drastic body adjustments. His chicken-wing style is a bit more handsy and less reliant on changing his eye level, and as a result, he has excellent plate coverage. His contact rates on pitches at the top, bottom, and outer thirds of the zone outpace Julien by about eight percentage points in each location.

Two other factors, which are not publicly available, also likely contribute to Freeman’s superior plate coverage: Horizontal Bat Angle (HBA), the horizontal angle of the bat at impact, and bat speed. Freeman, who we’ve already established has a steep VBA on average, appears to be better at altering his swing speeds when necessary, which lets him manipulate his bat angle to cover pitches throughout the zone. You can see this in the third video above, on the changeup breaking down and away from him.

Freeman’s approach also helps him produce against lefties (career 120 wRC+), which is something he has improved upon as he has gotten older (139 wRC+ over the last three seasons). Meanwhile, Julien’s daddy-hack approach sometimes limits his ability to alter his swing speeds and angles, which can often lead to poorly timed swings or mishits and explains why he is prone to hitting groundballs (50.2% last year) despite his steep swing. These issues are more apparent when he faces lefties (22 wRC+, 80% groundball rate), though as Davy pointed out in his Julien piece, he has made only 48 plate appearances against lefties in the big leagues — an incredibly small sample size.

That brings us to the next hitter, Tim Anderson. Even with his steep 39.5-degree VBA, Anderson had a groundball rate above 60% last year. A batter’s contact point has to be extremely deep to pull that off. Here are some swings from him to illustrate that:

Most hitters would struggle to put the ball in play after letting it travel this deep, but TA’s steep barrel and feel for contact in the zone allowed him to pound the ball into the ground over and over and over again last season. The sweeping breaking ball from Rich Hill is the exact type of pitch Anderson would have elevated in years past. Typically, having a steep bat path against an opposite-handed breaking ball is a perfect recipe for an ideal launch angle distribution, but if you’re making deep contact, this is all you can get out of the swing.

Chas McCormick was the anti-Anderson last season, when he mostly refused to hit the ball on the ground against opposite-handed pitching. He can do this because of how he marries his steep, 38.2-degree VBA with ideal contact points. In 2023, he had a 25.6 GB% against left-handed pitchers. That was the third lowest in baseball behind Jorge Soler and Mookie Betts. Unsurprisingly, by wRC+, they were three of the six most productive right-handed hitters against lefties last year. Here are a few swings from McCormick vs. lefties that show his ability to elevate no matter the zone or pitch:

Even on the well-executed curveball from MacKenzie Gore, McCormick’s barrel was on an upward slope at contact because he connected with the pitch out in front of the zone. This is the type of pitch that Anderson would have pounded into the ground despite the similar steepness at contact, because he would’ve let the pitch get deeper before swinging.

McCormick’s closed stride puts him in a great position to elevate any pitch in the middle of the plate, even if it makes it more difficult for him to square up inside pitches in the top half of the zone. That said, as you can see in the video of his swing against Cole Ragans, he can still get to up-and-in pitches when he holds his posture. The main takeaway is that no matter the zone, his barrel is working on an upward slope through contact, which allows him to do more damage.

Although their swings are similarly steep, these four hitters have different swing types that generate different results. VBA is a great tool to use, but it only tells one part of the story.

It is not easy to skip a whole year of something and come back with the same level of performance or skill. Baseball is no different, even for the best of ballplayers. Fernando Tatis Jr. missed the entire 2022 season because of wrist injuries and a suspension for using performance enhancing drugs. While he was serving his suspension, he underwent labrum surgery to repair a recurring issue that hampered his ability to consistently stay on the field. He was fully healthy upon his return in 2023, and he remained that way for the entire season.

Yet, despite avoiding injury for the first full season of his career, in 2023 Tatis had his least productive year at the plate. His 113 wRC+ was 41 points below the mark he had recorded over his first three big league seasons. He also set career lows in average (.257), on-base percentage (.322), slugging (.449), ISO (.191) and wOBA (.332). From a data perspective, his quality of contact took a significant hit, though that isn’t all that surprising. Even after athletes return to the field, it takes time for them to regain their explosiveness following serious injuries and surgeries. Ronald Acuña Jr. is a perfect example of that. He tore his ACL in July 2021, underwent season-ending surgery, and missed Atlanta’s first 19 games of 2022. Like Tatis last year, Acuña was mostly healthy for the rest of the season but did not perform up to his standards. Then, of course, last year he won the NL MVP and became the first player ever to hit 40 home runs and steal 70 bases in a season.

Tatis will look to take a similar path, but in order to do so, he’ll have to figure out and address the root causes (mechanics, swing decisions, etc.) of this big drop off. Back in September, Ben Clemens investigated how spray angle on fly balls impacts some of the hardest hitters in the game, Tatis being one of them. One of the key conclusions of Ben’s research is that hitters who pull their fly balls at an extreme rate, such as Isaac Paredes, don’t do more with those batted balls; they just hit them much more frequently, which allows them to outproduce others on fly balls, despite not having the eye-popping power that we’d assume would be the main causal variable.

This is notable for Tatis because, over his first three seasons, he hit the ball with enough power to do damage on fly balls no matter the spray angle. That was not the case last year.

From 2019 through 2021, Tatis’ wOBA on fly balls slightly outpaced his xwOBA, while last year, he greatly underperformed his expected numbers. Much of that can be explained by his pull rate dropping from 30.5% over his first three seasons to 21.8% in 2023. However, that’s not the only variable at play here, because even when he hit straightaway fly balls in those first three years, he had a .764 wOBA. That’s well below his .894 xwOBA, but it was still the third-highest mark among all batters from 2019–21 (min. 150 fly balls). Last season, though, Tatis finished with a .291 wOBA on straightaway fly balls, significantly lower than his .653 xwOBA. Crushing balls to the deepest parts of the park was once a Tatis superpower; in 2023, it was his kryptonite.

To better understand how this happened, let’s look at how Tatis fared in different areas of the strike zone. By breaking down his performance in different zones, we’ll get a better idea of any holes that may have developed in his swing. For all his woes last year, Tatis continued to rake against left-handed pitching (152 wRC+), so I’m going to focus on his splits vs. righties, against whom he had a career low 101 wRC+. The table below shows how Tatis performed against pitches from righties in each third of the zone, first in 2021 and then in 2023.

There are drops across the board here, but my goodness, what the heck happened on the outer third? In 2021, Tatis ranked second in right-on-right wOBA on outer third pitches. This year, if you were a righty who could locate on the outer third, Tatis would do the work for you.

What’s the deal? Making contact wasn’t the problem, because he actually whiffed less often against the outer third last year than he did in 2021. The real issue was his quality of contact. On his 67 batted balls against pitches from righties on the outer third in 2021, his xwOBACON was .634. In 2023, it was .305. Ooof.

A change in swing path is typically to blame when a player goes from destroying the outer third to hardly covering it at all. Let’s look at the video to figure out what mechanical flaws altered his swing path. Here are some swings from 2021 against outer third pitches from righties.

Here is a standard heater away with a pretty neutral body angle (sorry Keegan Thompson):

This one is a low and away breaking ball with a pretty aggressive body adjustment to get the barrel under the ball:

And lastly, here is a high heater that needed an upright body adjustment:

Each of these three swings shows how Tatis adjusted his body in different ways to get to his barrel to outer third pitches. The swings are reciprocal, athletic, and vicious. His stability with the ground is consistent no matter the posture of his upper body. Now let’s look at three swings on similar pitches from 2023, starting with another standard middle-away heater:

Here is a swing on a low breaking ball with a body adjustment where Tatis couldn’t quite create the same angle as he did in 2021:

Then here is a can of corn fly ball to center on an up and away heater where Tatis caught it off the end of the barrel:

OK, now for some comparison. Off the rip, it’s clear that Tatis’ stride is working in a different direction. It’s more neutral now than it used to be. Instead of working from a neutral stance into a closed stride, he’s working from an open stance into a neutral stride. The starkest comparison is looking at how he handled Thompson’s heater in 2021 versus the 2023 one we saw from Cristian Javier. Against Javier, it was the exact kind of pitch you’d expect Tatis to drill into the opposite field gap, but his legs didn’t create enough space for him to get his barrel moving in the optimal direction. Instead of a laser opposite field homer, it was a measly liner to left for an easy out.

In 2021, Tatis had a more stable base, which allowed him to create a more drastic angle with his upper body against the low breaking ball. That made the difference between his line drive in the gap from 2021 and last year’s line drive to the shortstop. On both of the high pitches, he had the tall posture he needed to get on plane, but in 2023, he couldn’t get his bat on the proper horizontal angle to make flush contact, causing him to hit the ball off the end of the bat instead of the barrel.

As I always say, we’re looking for reciprocal movements. If he’s still kicking back aggressively but doesn’t have the movement beforehand to make the kick back smooth, then he’s creating asymmetrical movements. The closed stride and smooth kick back was his recipe for success in 2021. The logic here is that when he strides closed, he has a more stable connection to the ground, leading to better positions to get his barrel on plane.

He did not do that last year, and as a result, he created less space for his upper body to cover the outer third effectively, which sapped his production on fly balls. Because he was coming back from surgery, it’s possible that he wasn’t comfortable making the same movements he had in the past, though it’s hard to believe that would be the only reason for losing his mechanics. After all, his surgery was on his shoulder, and this is a lower body problem. That said, even if he knew what was wrong, his shoulder could have limited the amount of extra swings he could take to fix it during the season.

Now that he is healthy, he should be able to do the drills and cage work necessary to correct his mechanics and return to his previous rotational patterns.