It's Wednesday, which means it's time for us to visit the bump on Hump Day and discuss starting pitcher news. Each week in this article, I'll be taking a deeper look at a few trending/surging starting pitchers to see what, if anything, is changing and whether or not we should be investing in this hot stretch.
The article will be similar to the series I ran for a few years called Mixing It Up (previously Pitchers With New Pitches and Should We Care?), where I broke down new pitches to see if there were truly meaningful additions that changed a pitcher's outlook. Only now, I won't just look at new pitches, I can also cover velocity bumps, new usage patterns, or new roles. However, the premise will remain the same: trying to see if the recent results are connected to any meaningful changes that make them worth buying into or if they're just mirages.
Each week, I'll try to cover change for at least four starters and give my clear take on whether I would add them, trade for them, or invest fully in their success. Hopefully you'll find it useful, so let's get started.
Most of the charts you see below are courtesy of Kyle Bland over at Pitcher List. He created a great spring training app (which he's now carried over into the regular season) that tracks changes in velocity, usage, and pitch movement. It also has a great strike zone plot feature, which allows you to see how the whole arsenal plays together.I'll also use Alex Chamberlain's awesome work with his Pitch Leaderboard.
With Triston Casas done for the season, Romy González has joined the top 300.
MacKenzie Gore - Washington Nationals (New Cutter, New Slider Shape)
Are you experiencing deja vu, or is this actually a MacKenzie Gore breakout? Last season, Gore had a tremendous first two months of the season, posting a 2.91 ERA, 1.28 WHIP, and 29.1% strikeout rate in 58.2 innings over his first 11 starts. Then the wheels started to wobble, and Gore posted a 4.43 ERA, 1.50 WHIP, and 22.5% strikeout rate over 107.2 innings in his final 21 starts. So now that the 26-year-old has posted a 3.33 ERA, 1.15 WHIP, and 36.4% strikeout rate in his first eight starts, you might be wondering if you're about to get hurt again.
The truth is that this seems like a new version of Gore. He may still hurt you (that appears to be in his nature from a fantasy baseball perspective), but this isn't the same MacKenzie Gore we saw last year. A big clue as to why can be found in his splits.
Last year, Gore had issues with lefties. He allowed a .282/.368/.466 triple slash overall, but even in the strong starts at the beginning of the season, you could see the cracks in the foundation. In those first eight starts, he had a 30% strikeout rate to righties, which dropped to 26% against lefties. His walk rate in those first eight starts was just 5.3% against right-handed hitters but ballooned to 12.3% against lefties.
When things got bad in the last four months of the season, they were worse against lefties. He had a 24% strikeout rate to righties in the tough stretch, but just a 19.5% mark to lefties. Over those final 21 starts, his Ideal Contact Rate (ICR) allowed was a whopping 50% to left-handed hitters, compared to a 36% ICR to righties. So if Gore was going to truly break out, he needed to do something different, particularly against lefties.
Turns out, he did two things: changed the shape of his slider and added a new cutter.
Last year, Gore's slider was a much harder pitch, averaging 91.1 mph with just 1.5 inches of horizontal movement and 7.3 inches of vertical break. He used it 28.5% of the time to lefties and 9.7% of the time to righties, which was an issue because it ate righties alive. The slider had a 22.6% swinging strike rate (SwStr%) and a 29.6% ICR to righties with a .182 batting average against, while posting an 11.6% SwStr% and 50% ICR to lefites with a .317 batting average against. Yikes. His curveball did post a slightly above-average swinging strike rate to lefites, but he didn't use it that often against them, instead throwing either a four-seamer or slider to lefties 81% of the time. Being that two-pitch focused against lefties and having one of those pitches get destroyed regularly is a recipe for disaster.
This year, he turned his old slider into more of a cutter and added in a slower slider. The new cutter is 90 mph with a little over 6 inches of vertical movement and just under one inch of horizontal break. That means it's a slightly tighter version of the pitch he threw last year. The new cutter grades out poorly on Picher List's PLV metric, but that's mainly because Gore is throwing it in the zone just 35% of the time, so his command of it is not elite. Yet, he's also posting a 26.5% SwStr% on it, and it has become a solid fourth offering to righties to go along with his four-seamer, curve, and changeup.
Gore uses the cutter inside to righties almost 70% of the time, which is nice because he doesn't go inside with his four-seam fastball nearly as much. The cutter has not just acted as a pitch to jam righties, but is a pitch that Gore will intentionally miss up with or run off the inside of the plate for a swinging strike. He's using it in two-strike counts 44% of the time to righties, and it's posted a 40% PutAway Rate, which measures how often a pitch thrown in a two-strike count leads to a strikeout. The cutter has, therefore, been an awesome offering to miss with a righty's timing and get whiffs.
But that doesn't help with the lefty problem. That's what the new slider is for.
Gore's slider in 2025 is 86.5 mph with just 2.5 inches of horizontal movement but essentially no drop. Considering he gets huge vertical break on his curveball, having the slider be a more horizontal pitch with less bite is a nice change, and you can see how it feels like a different movement profile to lefties from looking at Kyle Bland's chart below. The slider dots, in purple, are now more of a middle ground between the cutter (brown) and the curve (blue). He doesn't use all three to the same type of hitters, but he has created a more unique movement profile on his secondary pitches, which is nice.
So far on the season, Gore is using the new slider 42.5% of the time to lefties, still mixing in the curve but dialing back on the four-seamer a lot versus lefties. He's able to pound the zone with the pitch at an 85th percentile rate and also has a 26.4% SwStr% on it against lefties. The pitch is getting hit harder than we'd like to see, but he's using it almost 40% of the time in two-strike counts with an elite 34% PutAway rate, so the high ICR marks are on the rare occasions that hitters make contact. It's a new offering for Gore, so he does miss over the middle of the plate with it a bit more than we'd like to see, but you'd expect that to be corrected as the season goes on.
What we have right now is a pitcher who fixed his worst pitch against lefties, which was his biggest weakness. He also added a new pitch to prop up his strikeout rate against righties. There are still some overall command and consistency issues here, which could lead to some tough starts ahead against good opponents, but this version of MacKenzie Gore seems like a safer bet than the one we got last year.
Gunnar Hoglund - Athletics (Who is he?)
We had an intriguing rookie debut over the weekend when Gunnar Hoglund took the mound for the Athletics against the Marlins. The 25-year-old posted a 2.43 ERA, 1.04 WHIP, and 30:7 K:BB ratio in 29.2 innings at Triple-A this season. He has a five-pitch arsenal that features a four-seam fastball, sinker, and changeup as its foundation, and a slider and sweeper pairing that he mixes in as a fourth offering to lefties and righties, respectively.
It was just one MLB appearance for Hogund against a below-average opponent, so we don't want to overreact too much, but we got a sense of his approach, and I came away more or less sold on it.
I expect Hoglund to have more success against lefties, where he uses his four-seam fastball 46% of the time and his changeup 28% of the time. He also tosses his slider 23% and mixes in the odd sweeper here and there. The four-seam fastball itself is a solid pitch. It has solid 6.8 feet of extension and elite 18.9 inches of induced vertical movement. It's a relatively flat fastball that he uses middle and up the vast majority of the time and pounds the zone with at a 64% clip. Those are all things we like to see.
The changeup is the standout pitch, though. It has 17 inches of arm-side and tumbles out of the zone. It's why Hoglund throws the pitch in the lower third 73% of the time and has no problem using it as a two-strike offering. Even though he threw it early in the count nearly 73% of the time against lefties in his MLB debut, he only used it in two-strike counts against righties, getting two whiffs and two strikeouts on four pitches.
It's because Hoglund uses his sinker 40.5% of the time to righties that the changeup works. The sinker also has 17 inches of arm-side run but comes in at 93 mph instead of 87 mph and has far less drop. He loves to jam righties inside with the sinker, so when they start looking for it, he mixes in a changeup, which drops out of the zone and gets a swing-and-miss.
The only issue is that he can't do that too often and continue to fool hitters, which means he's going to be about 84% four-seamer and sinker to right-handed hitters. Those pitches are fine, and he's not likely to give up lots of hard contact given the pitch shape on the four-seam and impressive run on the sinker, but he's also not likely to miss many bats. In the one start we saw, the sweeper wasn't commanded well and didn't get a single whiff. It was the same for the slider (which is more of a cutter) against lefties. He commands that pitch better, but it got zero whiffs on the day.
What that means is that Hoglund profiles as more of a strike-thrower who will get some strikeouts against left-handed-heavy teams but be susceptible to giving up lots of contact. That might not always be hard contact, but he also plays his home games in a minor league ballpark that is going to see the ball start flying when the summer humidity sets in. That makes Hoglund an intriguing streamer who might be better used on the road.
60 undervalued players to help you win your fantasy league.
Lucas Giolito - Boston Red Sox (Season Debut, Fastball Shape, New Slider Shape)
(THIS ARTICLE WAS SUBMITTED BEFORE TUESDAY'S START. IT SHOULD BE NOTED THAT TUESDAY'S GAME FEATURED A RAIN DELAY AND RAIN DURING THE START, AND GIOLITO SAW HIS FASTBALL VELOCITY DIP TO 91 MPH. HE MADE IT THROUGH THE ORDER ONCE, ALLOWING 1 ER, 3H IN 3 IP BEFORE THE WHEELS FELL OFF IN THE FOURTH. HOPEFULLY THE 2.5 MPH VELOCITY DIP WAS CONNECTED TO WEATHER)
Lucas Giolito pitched on a MLB mound for the first time since 2023 last week when he took the ball on Wednesday against the Blue Jays. What we saw was an impressive first performance that had me trying to add him in leagues where I didn't have him stashed.
There were two things I saw that I liked. The first was that Giolito averaged 93.3 mph with his four-seam fastball, and that velocity has been important for him on that pitch over his career. When Giolito dips down under 92 mph, he's a completely different pitcher and a far less effective one. He also had elite 7.3 feet of extension with 17 inches of iVB, which gave him a flat attack angle on the pitch. It's possible that he also added some arm-side run to the pitch, but it could also be a small sample size blip. What we do know is that the fastball had juice, which we love to see, and, frankly, we need to see from him if he's going to be fantasy-relevant.
We also saw him lean into the changeup, throwing it 36% of the time in his debut (and 38% of the time to righties) after averaging 28% usage in 2023 with only 23.5% usage to righties. The pitch has slightly more movement this season, and he did a good job of keeping it low in the zone, so it can be a pitch that succeeds against hitters of both handedness. In fact, when Giolito has been running hot in his career, that changeup has been impactful to all hitters, so it's nice to see him go to it so often.
It's also clear that the Red Sox are working to reshape Giolito's slider. He said as much last year at spring training before he got hurt. In his debut, we saw a pitch that had over two inches more horizontal break and nearly four inches less vertical break. Giolito had talked before last season about how his previous slider had gotten too similar to a curveball in its movement profile, so adding the horizontal movement and cutting drop is a good thing for him. He threw just five in his debut, and it wasn't overly impactful, but I'm generally a fan of the direction the pitch is going.
At the end of the day, Giolito with that four-seam/changeup pairing is likely a Top-50 starting pitcher, and if Boston can figure out his slider, we could see a Top-40 season from him. We will need to see his fastball velocity hold if he's not going to take a big step forward with the slider, but after one start, he's certainly worth an add in any leagues where he's available, if only to keep on your bench and see how this plays out after another start or two.
Colin Rea - Chicago Cubs (New Arm Angle, New Slider, Pitch Mix Change)
THIS ARTICLE WAS SUBMITTED BEFORE REA'S TUESDAY NIGHT PERFORMANCE. THE STATS HAVE BEEN UPDATED, BUT THE ANALYSIS HAS REMAINED THE SAME.
Colin Rea has been one of the surprises of the early season, posting a 2.43 ERA, 1.21 WHIP, and 25:7 K:BB ratio in 29.2 innings for the Cubs across five starts and three relief appearances. The 34-year-old had put together two decent seasons for the Brewers as a primary starter over the last two years but nothing close to this level. So is he doing something different or just off to a fast start?
When digging into why Rea has been so successful early on in the season, there's not a lot that pops out.
His arm angle is down almost four degrees, which has shifted his overall movement profile a bit, adding vertical movement to his arsenal overall. We can see this in particular on his splitter, curve, and four-seam fastball. While the four-seamer itself has just a bit more induced vertical break, given the lower arm slot, the pitch has a flatter vertical attack angle in 2025 and has also gained one mph, which has caused it to have better grades of stuff models.
Rea is also leaning on the pitch way more, throwing his four-seamer 51% of the time after using it just 19% last year. Yet, doesn't stand out as a pitch he needed to throw more. Last year, his four-seam fastball had a solid 13.6% swinging strike rate but a 45% ICR and was more of a two-strike offering, with Rea throwing it 49% of the time in two-strike counts. This year, Rea is no longer just using it up in the zone, but is filling up the strikezone with it and throwing it early in the count over 63% of the time, using it in two-strike counts only 22% of the time. The pitch is missing fewer bats and still giving up a 47% ICR, so the approach is a bit confusing to me. My best guess is that the Cubs like how Rea can use the four-seamer to pound the zone for strikes and then use a deep arsenal of six other offerings to play off the four-seamer for weak contact. Kind of like what Milwaukee did with Tobias Myers last year.
As you can see from his pitch plot from his last start against the Pirates (chart courtesy of Kyle Bland at Pitcher List), Rea has plenty of pitches that can attack all areas of the strike zone once he gets ahead in the count.
To righties, he will primarily rely on a sweeper, cutter, and slider trio, and also mix in the sinker. As you can imagine, the sinker has a similar velocity to the four-seamer but more arm-side run, which should create minor deception. Only, it's not really a good pitch and gets hit hard. The slider, cutter, and sweeper range between 82-87 mph with varying amounts of horizontal movement, but all are designed to attack righties away. If Rea can get ahead with the four-seam fastball, it will be hard for hitters to identify which of the three pitches they're seeing out of his hand as he begins to attack them away. That's likely a big part of why he has a 13.4% SwStr% and 35% ICR against righties this season.
However, Rea has struggled more against lefties this season, primarily because he doesn't throw the sweeper or slider to them, or really the sinker either. That means Rea gets ahead with the four-seam fastball and then works in a curveball, splitter, and cutter that don't tunnel well or play off one another well. That's part of the reason he has just a 20% strikeout rate and 47% ICR against lefties. There is far less deception here.
All of this is to say that what Rea is doing is not overly impressive, but it does make sense that he's succeeding against righties. If his four-seamer continues to have the added velocity and movement, he can get ahead in the count and confuse hitters with six potential secondary offerings. However, since he relies so much on deception, I would avoid him against good teams or teams loaded with left-handed hitters.
JP Sears - Athletics (New Arm Angle, New Pitch Mix)
I've been talking a lot about arm angles so far this season since the guys mentioned it on the "Rates and Barrels" podcast, and Alex Chamberlain's Pitch Leaderboard update now allows us to see exactly who has shifted their arm angles the most. It's been fun to dig in. One of the pitchers who has made a significant change is JP Sears, who has raised his arm angle over four degrees and cut horizontal movement from his arsenal while adding to his vertical attack angle. Perhaps that's part of the reason he has a 2.93 ERA and 32 strikeouts in his first 40 innings this season.
Against righties, it seems like the biggest change has been leaning into his two slider variations more often. The sweeper has a little bit of added depth this season, but Sears is using it far more early in the count and not focusing as much on burying it down in the strike zone, which is good because sweepers down and in to opposite handed hitters tend to be a recipe for disaster. He has a 97th-percentile zone rate on the sweeper when using it to righties, and I think a big reason for that is because he uses it to set up his slider, which is tighter and flatter this season and has thrived as a two-strike pitch. Sears uses it 66% of the time with two-strikes against righties, and has a solid 16.4% SwStr on it.
He has also turned to the changeup more often earlier in the count, using it 81.5% of the time early in counts to righties. All of which is to say that Sears' shift to pitch backwards against righties has been successful. He can get ahead with his sweeper or change, and then go to the tighter slider or four-seam to try and steal strikes. It's still not an approach that seems to lead to lots of strikeout upside, but it has worked in limiting hard contact.
He's doing similar things against lefties, throwing his sweeper 65% of the time overall, using it early in the count 60% of the time, and registering a 59% zone rate on it against lefties. He's able to throw it in the strike zone against lefties and then shift it farther outside to have it break off the plate in two-strike counts. When he doesn't do that, he tries to spot a four-seam fastball away from lefties, using it 24% of the time to them and throwing it on the outside part of the plate 80% of the time.
It's essentially a two-pitch mix to lefties, with the slider mixed in, but he has a 20.6% SwStr% and 33% ICR on the young season, so it's working. I just don't know how much longer it will work, especially against right-handed hitters. The overall swinging strike rate is still poor, and it feels like hitters will start adjusting to Sears once they figure out his plan for attacking them backwards and get a better read on the slightly new shapes of his pitches, thanks to his new arm angle.
Matthew Pouliot
