WARNING: This is going to be nerdy.
Baseball Savant published new public bat tracking statistics this week that cover the last three seasons. I have no idea where this rabbit hole is going to lead me, but I have a notebook full of initial ideas to explore, so that’s what we’re going to do here today.
Mike Petriello put out a primer on the new metrics here. You should read it. If you don’t want to do that, the gist is that the new metrics track the bat during a swing in relation to the ball. They measure
how often hitters swing early or late, above or below the ball, and inside or outside the ball. Basically, are you swinging where you’re supposed to in order to make solid contact? We have this by count, pitch type, handedness, month, season (2023-present), venue, team, astrological sign, Hogwarts house, and more. Again, I don’t know what I’m going to find, but let’s dive in.
Four-seam fastballs are designed to get hitters to swing late and swing under the ball primarily. I’ve harped on how good Payton Tolle’s fastball is time and time again. Unsurprisingly, 62% of swings against his fastball have been underneath the ball, the 10th highest mark out of 289 qualifiers. That number is up from 45% last season. Why? Probably because of the addition of his sinker. That’s important because, despite his elite velocity, hitters are geared up for fastballs. They’re on time 72% of the time, 183rd of 289 qualifiers. Last season, without a second fastball, hitters knew both where and when to swing, which is a recipe for disaster. This season, there’s more pause about where to swing, and the contact quality has weakened.
Elsewhere, Brayan Bello has had a trainwreck of a season. Last year, he was incredibly effective at using his sinker to get out of jams. Hitters were “tied up” by 36% of the sinkers he threw last year. This season, that number is only 22%. What changed? Where he was throwing them.
In 2025, 55% of the sinkers he threw to righties were on the inner third of the plate and in. This season, only 46% of them were in that area. The hard hit rate against the pitch rose from 35% to 53% over that span. That hasn’t been Bello’s only issue this season, but it’s certainly been one of them.
What about great pitches? Garrett Whitlock’s slider returns “flawed swings” on 30% of swings. That means the hitter is not on time, lined up, or centered with his bat. If you think about the swing in three dimensions, timing, height, and width, it’s a swing that was 0-for-3. On whiffs, hitters miss by an average of 7.3 inches. That’s the 13th-largest average miss in baseball. Pretty good!
Let’s talk about cutters. The Red Sox love them, and they function in different ways. You can throw them back door to an opposite-handed hitter, trying to land for a called strike. They can also be used up and in to opposite-handed hitters, trying to jam them for weak contact. The former requires hitters not to swing, so these new stats don’t give us much information there. The latter requires one of two things to happen. Either the pitch moves more towards the glove side than the hitter expects, or they swing late and can’t get the barrel to the ball.
Brayan Bello’s cutter is a weird one. Against left-handed hitters, it has a huge swinging strike rate of 22.1%. The swing tracking numbers show us that lefties are regularly early (53% of swings, the second-highest rate among RHP to LHH), and never tied up (0%). Because they’re early so often, Bello needs the ball to really be in on their hands where they’ll have a hard time keeping it fair. Most of the swings, however, have been on pitches over the plate, allowing lefties to lift and pull the ball, leading to huge damage.
Payton Tolle’s cutter has been great — 31% of right-handed swings registered as “tied up”. Righties haven’t barreled the ball up at all, and the only extra-base hit against it was this double.
Note: I’m writing this during Tolle’s start against the Rays. Another hitter just bounced a cutter off the plate for a double. Baseball is so strange.
Ranger Suarez’s cutter also has a 21% tie up rate against righties, though the whiff rate is much lower. Hitters are late on 25% of their swings, allowing the ball to get in on their hands. For Tolle, they’re early 20% of the time as they look for something harder, leading to whiffs. There are at least two ways to skin a cat.
Speaking of Suarez, his sinker has been excellent at jamming lefties, with a tied-up rate of 24%. That’s lagging behind Garrett Crochet, whose 40% mark against lefties is among the best in baseball. Connelly Early isn’t far behind him at 36%, which contributes to his sinker’s 56.5% ground ball rate versus lefties.
In the bullpen, Tayron Guerrero is throwing his sinker by everyone — 38% of swings are late. Believe it or not, that isn’t how Aroldis Chapman is getting his whiffs. Hitters are on time 84% of the time against Chapman’s sinker and 79% of the time against his four-seam. It’s the movement that’s getting them — 52% of swings are underneath his sinker, 41% are under his four-seam.
Who haven’t I talked about yet? Sonny Gray? His four-seam is hit at times, but it also does a good job tying up lefties. It’s not a traditional high-vertical four-seam; it has some cut action to it, allowing it to get in on lefties. His cutter also gets in on lefties, because it has even more cut than the four-seam. His sweeper and curveball both induce incredibly ugly swings, like this one that Salvador Perez missed by literally over two feet.
On the hitting side, Masataka Yoshida leads the team in “Perfect Contact” with a 38% rate. Caleb Durbin is second at 33%. Neither guy is striking out; they clearly each have great control of the barrel. Neither guy has high-end bat speed, though, so despite being on time and lined up, they’re not doing a ton of damage. Wilyer Abreu has been late against fastballs, and the results reflect that. He has a 25% whiff rate and .219 batting average against them.
Alright, I think that’s enough meandering from me. This stuff isn’t the end-all be-all of analysis, but it helps to be able to confirm what you think you know, or give context to why someone might be slumping. Go check out the leaderboard yourself and let me know what you find in the comments. Maybe you’ll be able to fix the offense, or salvage a pitcher. I don’t have any pull in the organization, but once I wrote that Payton Tolle should add a sinker, and he did, so maybe someone is paying attention. Or maybe they aren’t, and they came to that conclusion on their own. I also wrote that Brayan Bello would be okay as a starter, and he gave up 75 runs in the first inning the very next day, so what do I know? Okay, I’m done meandering for real now. I hope you enjoyed reading this as much as I enjoyed writing it.
