This is the year of the splitter. In 2024, 3.1% of all big league pitches thrown have been splitters compared to 2.2% in 2023, a year-over-year increase of 41%. Aficionados of the split-fingered fastball include former NPB stars like Yoshinobu Yamamoto and Shota Imanaga, longtime MLB users like Joe Ryan and Fernando Cruz, and an assorted collection of hurlers who’ve added a new splitter or featured one much more prominently in their arsenal this year. And few starters have scaled up their splitter usage more than the man atop the pitcher WAR leaderboard: Tanner Houck.

Houck has thrown a splitter his entire time in the majors, but he’s taken it to a new level this year by doubling its usage. Among qualified starters, Houck throws the sixth-highest percentage of splitters, while his splitter’s 110 Pitching+ ranks fifth, ahead of Ryan and Imanaga. The rise of Houck’s splitter, combined with the arsenal tweaks he’s made to throw it more, have transformed him from a mixed-role swingman to slam-dunk frontline starter.

Houck has spent most of his big league career straddling the line between starter and reliever. He pitched mainly as a starter during his 2021 rookie season, but never completed the sixth inning in any of his starts. His sophomore campaign saw him make multi-inning appearances out of the bullpen. Back in the rotation last year, he posted an ERA above five and struggled to get outs as his pitches lost their bite later in starts.

Aside from stamina, Houck’s delivery served as a hurdle to his abilities as a starter. While a handful of starters fire from low arm slots, Houck is one of the only true sidearmers currently in a big league rotation. He doesn’t have an outlier release point thanks to his tall stature and mechanics that carry him toward the first base side, but his arm angle is certainly the lowest among starters. Houck’s delivery provides a great viewing angle for left-handed hitters, who comprise the majority of his competition as opponents stack platoon bats against him.

In 2023, lefties slashed .271/.356/.502 against Houck, roughly the equivalent of having to face Rafael Devers for the entire season. But through his first 10 starts of this year, he’s held them to a line so poor I can’t find a qualified hitter whose numbers I can compare with it. Neutralizing the platoon advantage is a huge deal for a pitcher with his arm angle, and much of this impressive feat has to do with his splitter.

Let’s take a look at what Houck’s approach to pitching looked like before ramping up the use of his splitter. Like most low-slot pitchers, his two primary offerings are a sinker and slider, taking advantage of the east-west movement his arm action produces. Both these pitches are chart-topping in terms of movement, dropping more than average due to their lack of backspin, and his slider breaks to the left even more than most sweepers (though Statcast doesn’t classify it as one).

While these two pitches made right-handed hitters absolutely futile against Houck, sinkers and sweeping sliders tend to generate large platoon splits, compounding with the advantage lefties gain from seeing the ball clearly out of his hand. Houck’s slider drops so much that lefties can’t do much with it, but his sinker moves directly into the path of their barrels, eager to get hammered. In the past, Houck primarily used four-seamers and cutters as his hard offerings against lefty opponents, hoping the rising action would be enough to miss bats. But these pitches still had too much arm-side movement and didn’t generate upward Magnus force, instead staying on plane with lefty swings.

Houck’s approach to lefties wasn’t working, and he needed a change. In came the splitter. What was once a distant fourth offering became his offspeed weapon. He tinkered with its shape, adding nearly four inches of drop to make it more distinct from his sinker. He tightened up its command, finishing down in the zone more consistently and spiking fewer in the dirt. The end result of these adjustments is a lethal pitch that has been a key contributor to Houck’s success.

Houck’s splitter leads his arsenal in both swinging strike rate and putaway rate, indicating it’s already his go-to weapon in two-strike counts. And while it’s been successful at missing bats, the results it generates when batters put it in play may be even more impressive. His split has the lowest launch angle allowed of any individual pitch from a starter; it’s one of just a dozen with a negative average launch angle. After years of allowing lefties to crush the ball in the air, he’s inducing a higher groundball rate against lefties than righties in 2024. These underlying changes have manifested in big time results – lefties have just a .038 ISO against Houck this season and have yet to homer, and Statcast metrics like barrel rate confirm this is no fluke.

The emergence of Houck’s splitter has also cut down his walk rate significantly, as he’s jumped from the 42nd to the 88th percentile in avoiding free passes. Previously, Houck often nibbled around the zone against lefties, afraid of what they could do to his fastball and cutter. Now armed with a pitch that limits damage, he’s fearlessly attacking the strike zone, improving his splitter zone rate by 14 percentage points and his overall zone rate by nearly five.

The effectiveness of his splitter has also made Houck’s sinker a more effective strike stealer because hitters watch it go by expecting it to drop beneath the zone. Houck currently ranks second to Seth Lugo in called strike rate, getting ahead of hitters before disposing of them with the slider and splitter. His improved control of the count is a big reason why he ranks fourth in K-BB% increase relative to 2023.

What impresses me most about Houck’s splitter is the sheer frequency with which he deploys it against lefties, especially at the expense of his fastballs. He’s throwing significantly fewer cutters and has shelved the four-seamer entirely. After unsuccessfully throwing the kitchen sink against opposite-handed opponents, he’s essentially become a two-pitch pitcher against lefties, throwing either a slider or splitter nearly three-quarters of the time.

It’s not often that you see a pitcher use two different non-fastballs as their primary offerings, but this strategy has paid off – not just for Houck but also for the Red Sox as a whole. Last month, Chris Gilligan wrote about Boston’s staff leading the leaguewide shift away from the fastball, pointing out Houck’s four-seamer had a horizontal movement profile ripe for hitters to feast on. Just a couple decades ago, a starting pitcher who almost exclusively relied on sliders and splitters against left-handed hitters would have been unthinkable, but the secondaries-first approach is now a strategy that entire teams are embracing with tremendous results.

Houck’s run as the top-performing pitcher in the majors probably won’t last — he has an unsustainably low 2.6% HR/FB rate — but the excellence of his splitter has certainly put a massive up arrow on his future projection. Just a couple years ago, it would’ve been difficult to envision that the sidewinding swingman who couldn’t handle lefties would become an excellent starter who consistently works into the seventh inning. But with a surprisingly simple fix, Houck has made it happen.

Welcome back to Top of the Order, where every Tuesday and Friday I’ll be starting your baseball day with some news, notes, and thoughts about the game we love.

Losing your starting shortstop and no. 2 hitter all at once is one of the worst things that can happen to a team, but somehow, the Phillies have weathered the absence of Trea Turner better than anyone could have hoped. The All-Star departed Philadelphia’s May 3 game against the Giants (in which he also scored from second on a wild pitch!) with a strained hamstring; at the time, he was expected to miss about six weeks, though he is “progressing at a surprising pace given the original timetable,” as Matt Gelb of The Athletic recently reported.

Obviously, the Phillies would love to have Turner back ahead of schedule, but they have more than held their own without him. They are 12-3 in their 15 games since May 4, their first following Turner’s injury, and their 123 wRC+ is the second-best mark in the majors during that stretch, behind only the Yankees. Philadelphia’s success isn’t due to the other positions carrying the load; though they’ve certainly been playing well, too. Rather, Philadelphia’s shortstop platoon of Bryson Stott and Edmundo Sosa has combined for a 163 wRC+ over that 15-game span; that’s better than every other NL team’s shortstop production. Only the Orioles, led by Gunnar Henderson, have gotten more offense at short.

Since Turner went down, Stott leads the Phillies with a 230 wRC+ and ranks fourth in the majors among players with at least 50 plate appearances in that span. Meanwhile, Sosa’s 167 wRC+ as a shortstop is the second-best mark since May 4, behind Henderson (187). Catcher J.T. Realmuto (153), first baseman Bryce Harper (180), and DH Kyle Schwarber (129) have also propelled the offense over these last 15 games. Additionally, the Phillies have received surprising contributions from utilityman Kody Clemens, who’s popped a couple of homers and has a 183 wRC+ across his 25 plate appearances since he was recalled to replace Turner on the roster. Even right fielder Nick Castellanos has woken up a bit, mustering a respectable 117 wRC+ during the 15 games without Turner after having posted a woeful 42 wRC+ from Opening Day through May 3.

On the other side of the ball, Phillies pitchers have kept up their end of the bargain for pretty much the whole season, and they’ve continued to perform well over the last 15 games, ranking fifth in ERA (2.78) and third in FIP (3.22).

All in all, even without Turner, everything’s clicking for the Phillies this season. They enter play Tuesday with a five-game lead over the Braves in the NL East, with the highest scoring offense (5.33 runs per game) and by far the most valuable pitching staff (9.3 WAR) in the majors. As Jake Mailhot noted in yesterday’s Power Rankings, Philadelphia has played the weakest schedule in baseball so far this season, so perhaps the team won’t maintain its .708 winning percentage the rest of the way. Even so, the Phillies have been winning at an .800 clip without their superstar shortstop. That is certainly encouraging.

Quick Hits

Let’s run through some other notable things from the past few days of games:

• The Yankees’ seven-game winning streak was snapped Monday night in heartbreaking fashion, when closer Clay Holmes allowed his first four earned runs of the season to blow a 4-1 ninth-inning lead against the Mariners in an eventual 5-4 Seattle win. Nevertheless, New York is playing its best baseball of the year right now. Aaron Judge has continued his reign of terror on opposing pitchers, going his 14-for-28 with 10 extra-base hits, including four homers, in his last eight games, and after a mini-slump, Juan Soto is catching fire again; over his last four games, he is 7-for-15 (.467) with two homers. Luis Gil, who wouldn’t have made the rotation if not for Gerrit Cole’s injury, struck out 14 in his start on Saturday. The Orioles lost on Monday as well, keeping the Yankees’ division lead at two games. The two sides don’t meet again until June 18.

• Like the Yankees, the Astros also coughed up an early lead on Monday night after a recent stretch of excellence. Houston led 6-1 before the Angels scored seven runs in the top of the fifth inning in what ended up as a 9-7 Astros loss. Still, the Astros have won each of their previous three series and jumped back into the AL West race after their dreadful start. They enter play Tuesday 4.5 games behind the first-place Mariners. Less than two weeks ago, on May 8, they were 8.5 games back. Yordan Alvarez still isn’t hitting anywhere near his abilities — though perhaps a double, single, and walk on Monday portends the start of a hot streak — but Alex Bregman has woken up and Kyle Tucker is playing like an MVP.

• Red Sox third baseman Rafael Devers set a franchise record Monday night when he homered in his sixth consecutive game. His home run, a two-run blast, came in the fourth inning off Rays righty Taj Bradley and extended Boston’s lead in its 5-0 win. Over his last six games, Devers is 7-for-24, his only non-homer hit being a single, with a 1.042 slugging percentage. With his home run Monday night, Devers surpassed the six other players who went yard in five straight games with the Red Sox: Bobby Dalbec (2020), Jose Canseco (1995), George Scott (1977), Dick Stuart (1963), Ted Williams (1957), and Jimmie Foxx (1940). The major league record for consecutive games with a home run is eight, shared by Dale Long (1956), Don Mattingly (1987), and Ken Griffey Jr. (1993).

Kyle Harrison was pitching for the Double-A Richmond Flying Squirrels when he was first featured here at FanGraphs in August 2022. Then a fast-rising prospect in the San Francisco Giants system, the now-22-year-old southpaw had broken down the early evolution of his arsenal for me prior to a game at Portland, Maine’s Hadlock Field. Fast forward to this past week, and we were reacquainting at a far-more-fabled venue. Harrison was preparing to take the mound at Fenway Park for his 14th big-league start, his seventh this season.

As I’m wont to do in such scenarios, I asked the dark-horse rookie-of-the-year candidate what’s changed since our 20-months-ago conversation. Not surprisingly, he’s continued to evolve.

“I’ve added a cutter, although I haven’t thrown it as much as I’d like to,” Harrison told me. “Other than that, it’s the same pitches. The slider has been feeling great, and the changeup is something that’s really come along for me; it’s a pitch I’ve been relying on a lot. I really hadn’t thrown it that much in the minors — it felt like I didn’t really have the control for it — but then all of a sudden it clicked. Now I’ve got three weapons, plus the cutter.”

Including his Thursday effort in Boston, Harrison has thrown his new cutter — Baseball Savant categorizes it as a slider — just six times all season. Which brings us to his other breaking ball. When we’d talked in Portland, the lefty called the pitch a sweepy slider. Savant categorizes it as a slurve.

What is it? Read the rest of this entry »

Wilyer Abreu has been one of the top rookies in baseball this season. Along with playing above-average defense in right field, the 24-year-old Boston Red Sox outfielder has logged a 155 wRC+ while slashing .316/.396/.519 over 91 plate appearances. His 1.1 WAR ranks second among rookie position players, behind Baltimore’s Colton Cowser. Granted, less than a month’s worth of games is hardly enough time to know if he’ll keep this up, but Abreu’s strong start is encouraging nonetheless.

He similarly impressed last year in a 28-game cameo. Debuting in late August, Abreu went 24-for-76 (.316) with two home runs, the exact same numbers he had this April. There’s juice in his bat. Eric Longenhagen wrote last summer that Abreu “has above-average raw power,” and the youngster’s production has backed up that prose. By the time of his call-up, Abreu had gone yard 22 times, with a 135 wRC+, at Triple-A Worcester.

His path to the big leagues included more than your typical climb up the minor league ladder. The Red Sox acquired Abreu from the Houston Astros, along with Enmanuel Valdez, in the trade for Christian Vázquez on August 1, 2022 — but that’s also only part of the story. The Maracaibo, Venezuela native had intended to sign with Boston in 2016, but the Red Sox were locked out of the international amateur market in 2016-17 as punishment for violating international-signing regulations. Abreu subsequently signed with the Astros in 2017; he waited an extra year to sign because he was told he’d get a better offer if he did.

He’s evolved as a hitter since inking his first professional contract. Read the rest of this entry »

Justin Slaten is well on his way to becoming a Rule 5 success story. Selected by the Mets out of the Rangers organization this past December and subsequently swapped to the Red Sox on the same day, the 26-year-old right-hander has come out of the Boston bullpen eight times and relinquished a single run in 14 1/3 innings. Moreover, he’s been stingy with baserunners, allowing just six hits and a pair of free passes. Four weeks into the season, he’s been the team’s top reliever.

His lone low moment to date came in his major league debut. Pitching in Seattle in the third game of the season, Slaten surrendered a 10th-inning walk-off single to Julio Rodríguez on his fifth big league pitch. Since that time, he’s been borderline flawless — opposing hitters have gone a paltry 5-for-45 against his power arsenal, with a Mike Trout triple accounting for the only extra-base knock. He’s punched out 11 batters.

Slaten’s mix — 38.5% cutters, 35.2% sweepers, 24.0% four-seamers, 2.2% curveballs — has been more varied than he expected it to be when he broke camp. Other than that, he’s mostly the same hurler who attracted Rule 5 interest by overpowering hitters while pitching with the Rangers’ Double-A and Triple-A affiliates last year.

“My only approach coming in was to throw everything in the zone, trying to get the best results,” Slaten told me before a recent game. “The only thing that has changed a little bit is the pitches that have been called. I’m probably throwing a higher percentage of breaking balls than I have in my entire life. But nothing has changed about the way I throw them, or try to execute.” Read the rest of this entry »

Welcome back to Top of the Order, where every Monday, Wednesday, and Friday, I’ll be starting your baseball day with some news, notes, and thoughts about the game we love.

Blake Snell’s Giants tenure couldn’t be going much worse. In three starts spanning just 11.2 innings, he’s allowed 15 runs — nearly a third of last year’s total in only 6.5% of the innings — with a hard-hit rate that’s up nearly six percentage points from last year. Some of his woes can be attributed to small samples and bad luck — his 11.57 ERA is much higher than his 4.05 xERA — but this clearly isn’t how he and San Francisco drew it up. And that was before news broke Wednesday that the Giants were placing Snell on the 15-day injured list with an adductor muscle strain in his groin area. He has dealt with this injury twice before in his career, though he doesn’t seem worried that it’ll a long-term issue:

Snell had the same injury in 21 and 22, says he caught it early and is hopeful he misses minimal time. Maybe just slightly more than the 15 day minimum.

— Susan Slusser (@susanslusser) April 24, 2024

After his disappointing free agency, Snell could at least look forward to the possibility that he’d earn $32 million this year and pitch well enough to opt out and seek a more lucrative deal after the season. But now that he is going to miss at least three starts, following his three clunkers, it appears unlikely that he’ll be in a position to risk the $30 million he’s set to make next year if he stays.

The more immediate concern for the Giants, though, is how they’ll fill Snell’s spot in the rotation. Logan Webb is on a roll (29 innings in his last four starts, with just three runs allowed), and Jordan Hicks is pitching quite nicely, with a 1.61 ERA in five starts. Keaton Winn (3.54 ERA) is also chipping in on the back end, and while top prospect Kyle Harrison has struggled to a 5.00 ERA so far, there’s certainly room for him to get better. The fifth spot, however, looks like something of a mess.

The Giants had hoped Alex Cobb would be in the rotation by now after he recovered from hip surgery more quickly than expected, but he strained his elbow as he ramped up and was transferred to the 60-day IL instead. That leaves the Giants with two options: go with bullpen games, as they did in a pinch on Wednesday when Snell was scratched, or bring up someone from Triple-A. The latter feels far more likely, especially with Mason Black (1.53 ERA in four starts) pitching very well with Sacramento. Black hasn’t thrown more than five innings or 70 pitches in a start this year, so he won’t exactly take the load off San Francisco relievers, who have the second-highest bullpen ERA in the majors. Still, promoting Black appears to be the best way through this unfortunate situation.

…

On the opposite coast, the Red Sox placed Opening Day starter Brayan Bello on the IL with lat tightness, joining fellow starters Lucas Giolito, Nick Pivetta, and Garrett Whitlock. As with Snell’s injury, Bello seems to have avoided serious injury, but in the best division in baseball, Boston can hardly afford to miss its no. 1 starter for even the minimum 15 days.

Rather amazingly, despite all those injuries, the Red Sox have the lowest ERA and FIP in the majors, with Kutter Crawford leading the way with a 0.66 ERA (two earned runs in 27.1 innings) that’s backed up by an also excellent 2.28 FIP. Tanner Houck (1.65 ERA/2.24 FIP) has become indispensable as well.

But things get dicey after that. The rest of the rotation now consists of Cooper Criswell, Josh Winckowski, and Chase Anderson, and because the latter two opened the season as relievers and aren’t stretched out to start just yet, their outings have turned into bullpen games.

This creates an awfully precarious position for the Red Sox bullpen, which has performed well thus far but doesn’t have the depth to cover an extended workload. Boston has already tapped into its pitching pipeline by calling up Criswell, and none of its other Triple-A pitchers are performing well enough to warrant a promotion to the majors. Moving Winckowski and Anderson to the rotation, then, has the compounding effect of weakening the bullpen, especially since Winckowski had pitched in high leverage situations.

Checking in on Wyatt Langford

Things certainly haven’t been rosy for Rangers rookie Wyatt Langford, who is batting .253/.337/.308 (89 wRC+) with no home runs across 104 plate appearances.

The 22-year-old has excellent raw power but just hasn’t tapped into it in the majors yet. His average exit velocity and hard-hit rate are both well below league average, with his barrel and sweet spot rates just barely above it.

It’s not all bad for Langford; he has elite speed that’s allowed him to beat out some infield hits, and his swing decisions are generally good, with chase and contact rates both well better than major league averages. But having great plate discipline can sometimes handcuff batters when they’re scuffling, and that seems to be the case with Langford. He’s talking too many pitches over the heart of the plate.

Pitch selectivity is a skill that depends just as much on swinging at the right pitches as it does laying off the wrong ones. A hitter may not get his ideal pitch during an entire game, let alone a single plate appearance, and taking too many hittable pitches leads to a lot of pitcher’s counts. It appears Langford would be much better off swinging more and using his quick hands and raw talent to make the most out of the pitches he gets over the plate rather than waiting around for the best possible one.

Ribs have been in the headlines this week, but sadly, not as part of a review of exciting new ballpark barbecue offerings. On Monday, Triston Casas was diagnosed with a fractured rib on his left side, an injury that will result in a prolonged absence and comes at a time when the Red Sox infield has already been depleted. On Wednesday, the Cubs’ Cody Bellinger was diagnosed with fractured ribs on his right side, interrupting his rebound from a slow start.

The 24-year-old Casas left Saturday’s game against the Pirates after injuring himself while fouling off a Mitch Keller pitch. He was initially diagnosed with a strain in his left rib cage and was placed on the injured list on Sunday. An MRI taken on Monday revealed a fracture as well, and the presumption is that his absence will be a long one given that the damage involves muscle and cartilage as well as bone. “Timetable, there’s none. It has to heal on its own. We’ve just got to be patient,” said manager Alex Cora. That sounds like a trip to the 60-day IL could be in order. Read the rest of this entry »

When I interviewed him 12 months ago, Logan O’Hoppe told me that he keeps two journals. One is for baseball. The other is for life. As the then-rookie catcher explained, “It’s tough to stay in a consistent headspace day to day,” and writing down his thoughts helps keep him centered.

One year later, he’s not only taking his game to a new level — O’Hoppe has a 137 wRC+ over 70 plate appearances — he’s also upping his journal input. I learned as much when I asked the LA backstop if he ever writes about the ballparks he visits. Moreover, I learned those visits are atypical of most major leaguers’.

“I’ve got three different ones now,” O’Hoppe explained when the Angels played at Fenway Park earlier this month. “One is for the game-planning stuff with the pitcher, and another is for hitting; those are obviously all baseball. With the third one, yes, I write a lot about the ballparks. It keeps my perspective in line. Early on last year, when I was really new to [the big leagues], I tended to think that this was the end all be all, and that the results were everything. I’m trying to realign my perspective and understand the results for what they are. I feel like it’s really helped me to come to different ballparks like this one, and sit alone in stadiums that I was at growing up.”

Adam Wainwright did something similar toward the end of his career, visiting various locales in ballparks, such as press boxes and concourses, prior to games. O’Hoppe is doing something similar, only on the front end of his career. Read the rest of this entry »

Life in the minor leagues differs greatly from life in the majors, often leaving those who climb the affiliated ladder with a multitude of stories. While some of those experiences are amusing in hindsight, many of them also underscore why minor leaguers fought so hard to unionize in an effort to improve their pay and working conditions. From torturous bus rides to cheap motels and ballpark mishaps, life before players make the big leagues can leave you laughing – and shaking your head. Here is a collection of a few such stories, courtesy of nine people in the game well versed in life on the farm.

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Liam Hendriks, Boston Red Sox pitcher:

“The minor leagues are character building. You go through the adversity to get to the [big leagues], and the juice is worth the squeeze. It’s been a minute since I’ve been down there, but the minors are just a grind. You wake up early in the morning to travel to the next town, then you stay in shitty hotels. You learn to find the silver linings in everything.

“One story I’ll always remember is Chris Colabello getting called up. He had spent [seven] years in indie ball, got signed as a 27-year-old to Double-A with the Twins, and I was with him in Triple-A in 2013. We were on the bus — I think it was Lehigh Valley to Rochester — playing cards in back. I don’t remember what game we were playing, but I had the best hand I’ve ever had in my life. One of the other guys had one of the best hands of his life. The manager, Gene Glynn, comes walking down. He says, ‘Hey Chris, got a minute?’ Tells him he’s getting called up. Twenty-eight years old, all those years grinding in indie ball, and he’s getting his first call-up. Calls his old man, was crying on the phone. Read the rest of this entry »

Tyler O’Neill didn’t take long to adapt to a new team. Traded to the Red Sox in December after spending six years with the Cardinals, O’Neill claimed sole possession of a major league record by homering on Opening Day for the fifth straight season. As we approach the two-week mark of the season — yes, it’s early — he finds himself atop major leaderboards and has helped Boston get off to a 7-4 start.

On Tuesday at Fenway Park, O’Neill launched a towering solo shot over the Green Monster off Orioles ace Corbin Burnes to put the Red Sox up 1-0 in the first inning:

The Statcast-estimated distance of 413 feet made that O’Neill’s longest of this season so far. It was his sixth homer, momentarily moving him out of a tie with Mookie Betts, Marcell Ozuna, and Mike Trout, though Trout countered with his sixth later on Tuesday night. Nonetheless, O’Neill has matched Fred Lynn’s hot 1979 start for the most homers by a Red Sox player in the team’s first 11 games of a season, doing so while making just nine starts and a pinch-hitting appearance. By comparison, last season O’Neill didn’t hit his sixth home run until August 11, and finished with just nine in 72 games.

O’Neill began the season by homering off Mariners reliever Cody Bolton on Opening Day in Seattle. In doing so, he broke a tie with Yogi Berra (1955–58), Gary Carter (1977–80) and Todd Hundley (1994–97) for the most consecutive Opening Day games with a home run. (And you thought you were glad baseball was back!) He closed out the Seattle series with a homer off Bryce Miller on March 31, took the Angels’ Griffin Canning and José Soriano deep on April 5, then added a dinger against Chase Silseth on April 7.

Unfortunately for the Red Sox, O’Neill’s blast on Tuesday was their only run of the day; they lost 7-1. And oddly enough, the 28-year-old left fielder hasn’t driven in anyone else despite his six home runs, which is more a commentary on his teammates than his own failings; he’s 1-for-3 with a pair of walks with runners in scoring position. Regardless of his RBI total, he’s swinging a very hot bat overall, hitting .344/.488/.906. It’s not every day you’re miles ahead of two future Hall of Famers for the major league lead in key categories, so we’ll note that his slugging percentage is 126 points ahead of the second-ranked Trout, and his 276 wRC+ is 32 points ahead of the second-ranked Betts. Meanwhile his on-base percentage merely leads the American League.

Of course, O’Neill has played just 10 games, the first nine of them against the Mariners, A’s, and Angels — all on the road — and there’s only so much we can take from that, but the number one thing is that he’s healthy, and that’s a big one, because save for his monster 2021 season and his brawny physique (“listed at 5-foot-11 and 200 pounds, of which about 198 pounds is biceps and quads,” wrote Michael Baumann), injuries have largely defined his career.

Drafted by the Mariners out of a British Columbia high school in the third round in 2013, O’Neill became a Cardinal in the Marco Gonzales trade four years later. He debuted in the majors on April 19, 2018, but spent much of that season and the next one bouncing back and forth between Triple-A and the majors, with five (!) trips to the injured list thrown in for good measure. After spending all of 2020 in the majors and on the active roster — and even winning his first Gold Glove, but hitting a miserable .173/.261/.360 — he finally got something close to a full-length season under his belt in 2021, hitting .286/.352/560 (143 wRC+) with 34 homers, 15 steals, and 5.3 WAR in just 136 games, but accompanying that with two more trips to the IL. He added a second Gold Glove that year, and finished eighth in the NL MVP voting, but since then he hasn’t come close to replicating that season, with injuries limiting him to just 168 games, 23 homers, a 98 wRC+ and 2.0 WAR across 2022–23, another two-year span that included five trips to the IL:

Thus the 28-year-old O’Neill entered this season having played more than 100 games in a major league season just once, and more than 72 just twice. Between his injuries, a crowded field of alternatives, his increasing price tag, and a spat with manager Oliver Marmol — who publicly questioned O’Neill’s effort running the bases during a heavy rain last April 4 in St. Louis, calling his effort “unacceptable” — O’Neill fell out of favor in St. Louis. On December 8, the Cardinals traded the pending free agent to the Red Sox in exchange for a pair of righty relievers, Nick Robertson and Victor Santos.

So far, the change of scenery seems to agree with him, though it’s worth noting that Tuesday’s game was his first at Fenway with the Red Sox. One game, one homer? That’s a pretty good rate!

In light of O’Neill’s long history of leg woes, it’s worth pointing out that as of now he’s hitting the ball harder than in the past two seasons. I present these stats while acknowledging that we don’t have enough data to draw strong conclusions about what’s happening yet; this is as much about his decline from 2021 as it is his torrid start:

Bear in mind that, as Baseball Prospectus’ Russell Carlton has noted, exit velocity stabilizes around 40 batted ball events, and barrel rate at 50 BBE, while groundball, fly ball, and hard-hit rates do so at 80 BBE. Within this small sample, this year’s exit velo and barrel rate at least look more like 2021 than ’22 or ’23. On a rolling basis of 25 plate appearances, both his xSLG and xwOBA show that his season-opening hot streak resembles only two or three stretches from the past two seasons, while he had a handful of such stretches in 2021:

The other thing to note about O’Neill is how much he’s tightened his approach so far. He’s a guy with a lot of swing-and-miss in his game, so much so that even as he ranked no. 61 on our Top 100 Prospects list in 2018, he had 30/40 grades (present/future) on his hit tool, and from 2018–23, he struck out 30% of the time, seventh among hitters with at least 1,500 PA in that span. Production-wise, he’s near the upper end among guys with strikeout rates in that neighborhood; of the hitters with the 30 highest strikeout rates over at least 1,000 PA within that span — everybody from 28.8% up — his 111 wRC+ ranks fourth, behind only Luke Voit (123), Giancarlo Stanton (122), and Teoscar Hernández (117).

Entering this season, O’Neill had swung at 72.5% of pitches within the strike zone, including 71% last year; so far this year, he’s cut that down to 50.8%. Similarly, his overall swing rate of 48.1% entering this year (44.9% last year) is down to 36%. His swinging strike rate of 15.4% (11.2% last year) is way down to 6.4%, and his strikeout rate, which was 25.2% last year, is at 19.5%. Mind you, none of these stats have stabilized — swing rate takes about 50 PA (he’s at 41) and strikeout rate requires roughly 60 PA — but those are at least promising trends.

We’re obviously still early enough in the season that any trend could be a mirage, a two-week heater or skid that might not merit closer scrutiny if it were located in mid-June or the dog days of August. Still, when combined with his hot streak, the health and change-of-scenery aspects of O’Neill’s situation are at least worth keeping an eye on. He’s not going to continue slugging .906, but for a team whose outfielders entered this season ranking 22nd in the majors with a combined 96 wRC+ since 2020 — i.e., the post-Betts era — this counts as a welcome development.