Back in October, my analysis “Mark Vientos: Simplified Power, Compact Efficiency” made the case that Vientos’s next developmental step was to “Learn How to See.”
Since Vientos remains on the roster as a high-upside player for the 2026 team, we need to drill down on why his 2025 season went sideways. After a breakout 2024 and a sharp regression in 2025, the popular explanation has been that Vientos became too passive—that he was taking too many good pitches early, falling behind, and then collapsing.
I reviewed the swing data alongside my previous mechanical breakdown to test this hypothesis. The findings are conclusive: Vientos possesses a "short, direct, and efficient" swing with a "connected" kinetic chain. He didn't slump because of his mechanics or passivity. He slumped because the league exposed his specific weakness in "secondary pitch recognition."
1. The Data Rejects the "Passive" Hypothesis
Vientos did not stop swinging. The data shows he was actually more aggressive in 2025 than during his breakout 2024 campaign, both on the first pitch and on pitches within the strike zone.
Table 1: The Aggression Metrics
Source: Baseball-Reference / Baseball Savant (Plate Discipline & Swing Stats)
The Reality: Vientos increased his aggression on the first pitch (30.6% to 32.8%) and attacked pitches inside the strike zone more frequently (Zone Swing % rose to 70.8%).
The problem was not intent; it was outcome. In 2024, his early aggression resulted in an elite 1.047 OPS. In 2025, that plummeted to .631. As I noted in my initial scouting report, his "sequencing" is solid and capable of "repeatable contact", yet the results dropped. This indicates he was swinging at "pitcher's pitches" on the edges rather than mistakes over the heart of the plate.
2. The Funnel: How One Missed Decision Becomes No Good Options
The hypothesis that Vientos struggles with two strikes is correct—but that is a symptom, not the cause.
My assessment of his Zone Coverage is that it remains "Limited", meaning he needs expanded plate awareness to sustain power. In 2024, he hid this weakness by doing damage early. In 2025, because his early aggression resulted in weak outs or fouls, he was funneled into pitcher-friendly counts at a much higher rate.
Table 2: The Funnel to Failure
Source: Baseball-Reference Splits
How to Read This: "sOPS+" measures a player relative to the league average (100). In 2024, Vientos was near-average at surviving 0-2 counts (82 sOPS+). In 2025, he found himself in that terminal count nearly 50% more often (57 times), and he was significantly easier to put away (70 sOPS+).
3. The Smoking Gun: The Fastball Paradox
This is the most critical finding in the data. The collapse in 2025 was driven by a sudden inability to punish the fastball—but not because he was missing it.
Table 3: Fastball Performance & Contact Quality
Source: Baseball Savant Pitch Tracking & Quality of Contact
The Insight: Vientos actually whiffed less on fastballs in 2025 (23.6%) than he did in 2024 (26.7%).
However, his Barrel % dropped significantly (14.1% to 11.5%). When a lower whiff rate combines with plummeting Slugging Percentage (.615 to .441), it signals weak contact. His biomechanical analysis identifies his contact plane as "steep-to-neutral", which naturally generates lift. When his timing is disrupted, this plane results in pop-ups or weak fly balls rather than line drives.
4. The Trap: Sinkers and Sweepers
Why was his timing off? The data validates my diagnosis regarding "spin deception”.
What is Run Value? Run Value measures the run expectancy added (or lost) by a player on every pitch. A positive number means production; a negative number means the hitter decreased the team's chance of scoring.
In 2025, pitchers stopped challenging Vientos with honest 4-seamers and started tunneling pitches that looked like fastballs but moved late.
• Sinker Run Value (2025): -5
• Sweeper Run Value (2025): -5
Both the Sinker and Sweeper are designed to mimic the 4-seam fastball out of the hand. The fact that Vientos posted a -5 Run Value against both confirms the need to improve "curveball/slider differentiation".
Conclusion: Harmonizing the Sequence
The data proves that the 2025 slump was not about passivity, nor was it a mechanical breakdown. My analysis confirms his lower-half usage is "Strong" and his kinetic chain is "Connected".
The issue is (visual) information dependence. In 2024, Vientos crushed fastballs because he saw them clearly. In 2025, the league adjusted by disguising fastballs with Sinkers and Sweepers.
The Fix: The path forward is not a swing overhaul. As I outlined previously, the focus must be on "approach refinement" rather than mechanical change. The challenge for the Mets' hitting lab is "harmonizing the body’s sequence and the brain’s recognition window".
If Vientos can "Learn to See" and lay off the Sinker/Sweeper tunnel early in the count, his simplified power will play again.
10 comments:
Well, as someone that has always rooted for players most others want to get rid of, I hope Vientos can re-adjust to the adjustment the league made.
But, is it only recognition? In 2024, Vientos seemed happier playing. He was the last cut in spring training after having a 35% strikeout rate but leading the team in HR when the Mets signed JD Martinez. But, when he got promoted, he played third base and hit. Last year, he wasn’t in the field as often and as for hitting, well… sometimes. He never seemed relaxed of in a good groove. That player that was punishing the Dodgers in the playoffs is still there and I’m glad he has a GM like Stearns that doesn’t read the papers, because most others would have sent him to San Diego for Laureano by now.
I’m very familiar with this subject. And disagree.
Going from 30% to 32% on first pitches is in and of itself very conservative. Brent Rooker was floundering as a professional into his late 20s, and then started swinging at a very high rate on first pitches and went from reject to Star. Simply put, and I’ve mentioned this a number of times, Vientos got to two strike, counts in53% of his plate appearances.. In those 53% of his plate appearances, he hit an bysmal .133. So, if I’m a doctor writing him a prescription, I’d be telling him to take that rate up to 45% or even on first pitches, because getting to two strikes is clearly a devastating place for him to be. His .133 in those 53% of plate appearanceswas accompanied by a very low on base percentage and a very low slugging percentage. Basically, in those 53%, he hit like Jerry Koosman. If I were Mark, which I’m not, I would follow my prescription. He might just be the next Brent Rooker.
He also fanned 115 times in the 248 times he got to 2 strikes. How many plate appearances and strikeouts would occur if he was much more aggressive on strike one? Mathematical logic would dictate that both numbers would become a smaller relative proportion of his total plate appearancesIf you’re only swinging it two pitches, rather than three, my guess is you’re going to shrink out more. He is not JuanSoto, part of whose skills include an amazing ability to work out walks in large numbers. So, MV just can’t take pitches the way Soto can and be successful.
I'm with RVH on this. If you can't tell what the pitch is, whether it's the 1st,2nd or 10th, you are going to lay off, make a weak defensive swing, etc. You are most importantly, going to lose confidence. So, I don't see any reason not to believe that the first skill he needs to develop is pitch recognition. Only then can he adjust to the adjustments made by pitchers.
In 2024, one of his strengths was an ability to get himself out of a slump, the exact opposite of what plagued Baty. They seemed to have reversed roles in 2025..
I think he is fixable but I don't know what is in his head. Why is he fixable. He has a short and direct swing. so in principle he can wait a bit longer so see spin and let the ball get a bit deeper..
I also believe that there are very few batters who can focus on covering the entire plate. Now kidding aside, I was a decent pitcher, but not much of a hitter, but I learned a lot about hitters by having to pitch to them. And if I had to express my views about how to be a successful hitter it would crudely be this: first, you have to optimize your kinetic sequence for your body type and flexibility, etc. Next, you have to realize that seeing comes before hitting. You have see the pitch and make a reasonably confident judgment about where it will be when it gets to the plate. Third, you have to develop an approach: what you swing at, what kind of swing you put on it, and what you don't unless you have to waste it. And then you have to put all this into your approach based on how many are on base, what you need to do to move them along or whether you have to swing for the fences, etc.
The key part is figuring out which pitches you can do what with. It may be that you can do real damage based largely on location or based on the kind of pitch or a combo of the two, whereas other pitches you can handle with success a reasonable amount of times, but you cannot drive. Others you cannot handle and that is usually a matter of location. So one of the first thing you decide is to let go pitches in certain locations unless you have no choice. You focus on a part of plate for damage in certain counts, other parts of the plate on other counts. You have to have not just an approach, but a plan that optimizes your strengths and minimizes your vulnerabilities.
As for Vientos swing mechanics they are generally very good, though steepness should be avoided to the extent possible. I much prefer level to shallow.
kinematic not kinetic
We agree to disagree. As I said, Rooker did it and became a feared slugger. So there is a concrete example of success.
“ The key part is figuring out which pitches you can do what with.” He began playing pro ball in 2017. If he hasn’t figured it out yet…
Pete Crow is at the other extreme. He swung at 53% of first pitches, an incredible rate. Despite a second half slump, he had 72 XBH, scored 91 runs, and drove in 95. I wonder how much worse he would’ve done if he swung it 32% of First pitches like Mark Vientos.
If Mark finds himself making worse contact on a number of pitches, how much worse can it be than hitting .133 in 53% of his at bats?
I am not saying that what I suggest is the only tool for him to improve is hitting, but I sure believe it’s an important one. As I mentioned before, if he starts being more aggressive on first pitches, pictures will be more cautious with him on first pitches, which will lead to more first pitch balls, putting them ahead in the count more often. Opposing pitchers, realizing the big power that Mark has, will be more cautious if they think he’s swinging at that first pitch aggressively. And if I were that opposing pitcher, I would be nibbling at corners and missing more pitches off the strike zone, hoping he’ll fish, not throwing it down the middle figuring he won’t swing and immediately get ahead in the count.
Anyway, that’s my take
No doubt that what you suggest makes sense. I view that entire process between pitcher and hitter as among the most intriguing and dynamic in activity in baseball. Both want to get ahead in the count, where their respective odds of success escalate. I would put your line of argument in the following way. I understand that you make it hard to get ahead in the count if you swing at the first pitch, but it is even harder to get ahead in the count if the pitcher (unless he has terrible control) knows you are not going to swing at the first pitch. It follows that you have to figure out the right balance; and swinging as infrequently as Vientos currently does has proven not be a successful strategy. But my response is that this means something has to change, but it doesn't tell you exactly what should change. For me, the main change that will be helpful no matter what strategy you adopt is to improve pitch recognition; that will help pick which first pitches to swing at and limit the extent to which you decide which to swing at randomly in order just to increase the number of first pitches you swing at.. and it also helps if your strategy is to continue to take first pitch es and become a better second pitch hitter.
Jules, the landscape of baseball is littered with hitters who fanned too much. But it is a ladder. Most guys fall off the ladder. Guys like Ted Williams and Barry Bonds atop the ladder, with great contact, and with Soto a little further down. Vientos has had real trouble, like so many, in climbing very far up that contact ladder. Wasting hittable strikes incurs a greater cost for those further down the ladder.
Manny Sanguillen swung at everything, rarely fanned, and hit .296. He wasn’t up there looking. He succeeded.
Tom-- Don't doubt a word you said. But it's not the right approach for everyone. Vlad swung at everything but he was amazing. And he had an uncanny ability to make solid contact with nearly everything thrown with 3 feet of the plate. Almost like a golf trick shot artist. For those kinds of players, the bat isn't a tool, it's a magical wand.
As I have said before, I just don't have a feel for Vientos as a hitter. I know I overvalue what goes on between the ears in sports, but barring insane natural talent, making it in sports involves working effectively on ones craft. and that begins, as I know from experience, in really understanding who you are, and what you can be by working on your craft and forgetting about who you would want to be.
Jules, I agree with that. And Vlad is up there with Soto and doing it just like his great Daddy did. Both knew what would make them optimal. Vientos hasn’t figured that out yet. Rooker did, though, after he floundered for a number of years.
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