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10 Most Notable Pitcher
Arsenal Changes in 2026
Data through April 12, 2026 — via Statcast pitch-level data
Every offseason, pitchers tinker. They add a pitch, tweak a grip, raise their arm slot a few degrees. Most of it doesn’t show up in the numbers. But sometimes a pitcher comes back looking like an entirely different animal – new shapes, new sequences, new results.
We dug through pitch-level Statcast data for every returning pitcher with meaningful innings in both 2025 and 2026, comparing velocity, movement profiles, arm angles, and usage rates. These ten stood out as the most dramatic and impactful arsenal overhauls of the young season.
1. Yusei Kikuchi — The Arm Slot Overhaul
What changed: Kikuchi’s arm angle jumped from 36.5° to 50.3° – the largest arm slot shift of any returning pitcher – and he’s added a brand-new cutter (19.7% usage) while overhauling his entire pitch mix.
| Pitch | 2025 Usage | 2026 Usage | 2025 Velo | 2026 Velo |
|---|---|---|---|---|
| 4-Seam | 34.8% | 25.9% | 94.8 | 95.1 |
| Slider | 36.2% | 22.3% | 87.0 | 86.1 |
| Changeup | 11.9% | 22.3% | 85.5 | 87.4 |
| Cutter | – | 19.7% | – | 90.4 |
| Curveball | 15.0% | 9.9% | 79.9 | 79.4 |
The slider-heavy approach from 2025 is gone. In its place is a four-pitch mix centered around the fastball, slider, changeup, and the new cutter, which is generating a team-best 36.0% whiff rate. The higher arm angle has also reshaped his fastball: IVB jumped from 15.4” to 18.6”, giving the heater significantly more ride. His overall whiff rate climbed from 23.6% to 30.1%, while K% (22.9%) and BB% (8.6%) have held steady. The early returns suggest this is a carefully planned mechanical and arsenal overhaul rather than just tinkering.
2. Emerson Hancock — The Sweeper Breakout
What changed: Hancock has essentially become a different pitcher. The sinker/changeup groundball specialist from 2025 is now a four-seam/sweeper whiff machine.
| Pitch | 2025 Usage | 2026 Usage | Whiff% ‘25 | Whiff% ‘26 |
|---|---|---|---|---|
| 4-Seam | 26.3% | 39.5% | 23.5% | 36.6% |
| Sweeper | 4.2% | 26.6% | 44.0% | 33.3% |
| Sinker | 39.2% | 19.1% | 9.3% | 12.1% |
| Changeup | 19.6% | 3.0% | 27.7% | 0.0% |
The numbers are staggering: K% has nearly doubled from 16.8% to 31.0%, BB% dropped from 8.8% to 5.6%, and chase rate exploded from 9.2% to 17.3%. By pairing the riding four-seam with a sweeper that moves in the opposite direction, Hancock has created a devastating tunnel that batters simply can’t solve. The changeup, which was nearly 20% of his mix in 2025, has been virtually scrapped. He’s also added a cutter (11.2%) that bridges the gap between the fastball and sweeper. This is the most dramatic performance turnaround tied to an arsenal change in 2026.
3. Dustin May — The Full Redesign
What changed: May raised his arm angle 9.3° (21.1° → 30.3°), gained nearly 2 mph on his fastball (95.4 → 96.8), flipped his pitch hierarchy, and added a curveball he didn’t throw in 2025.
| Pitch | 2025 Usage | 2026 Usage | 2025 Velo | 2026 Velo |
|---|---|---|---|---|
| 4-Seam | 16.7% | 29.8% | 95.4 | 96.8 |
| Sweeper | 38.9% | 21.4% | 85.2 | 85.8 |
| Sinker | 33.5% | 20.5% | 94.6 | 96.6 |
| Cutter | 9.6% | 11.2% | 91.4 | 93.4 |
| Changeup | 0.8% | 8.8% | 89.1 | 90.1 |
| Curveball | – | 8.4% | – | 82.8 |
May went from a sweeper/sinker pitcher to a four-seam-first guy with a full six-pitch arsenal. The velo spike across every pitch is notable – his sinker is sitting 96.6, and the four-seam at 96.8 is touching the upper-90s regularly. The added curveball gives him a true 12-6 shape that his 2025 mix lacked. His BB% has plummeted from 9.1% to 4.7%, though K% has also dipped (21.4% → 17.2%). The walk rate improvement alone makes this a net positive, and the mix diversity gives him far more ways to attack hitters.
4. José Soriano — The Fastball Pivot
What changed: Soriano was the quintessential sinker-baller in 2025 (49.7% sinkers). In 2026, he’s flipped the script, tripling his four-seam usage while cutting his sinker rate nearly in half.
| Pitch | 2025 Usage | 2026 Usage | Whiff% ‘25 | Whiff% ‘26 |
|---|---|---|---|---|
| Sinker | 49.7% | 27.8% | 15.4% | 29.4% |
| 4-Seam | 8.6% | 26.8% | 27.3% | 32.6% |
| Knuckle Curve | 26.1% | 25.9% | 42.2% | 45.2% |
| Split-Finger | 9.0% | 9.5% | 40.9% | 43.8% |
The results have been electric. His K% has jumped from 20.9% to 29.2%, and his overall whiff rate surged from 26.3% to 34.3% – one of the biggest improvements in baseball. The four-seam at 98.4 mph sets up the knuckle curve and splitter far better than the sinker ever did, creating a high/low dynamic that generates more swings and misses. Even his sinker whiff rate nearly doubled (15.4% → 29.4%), likely because hitters have to respect the elevated fastball now. The chase rate jump (14.4% → 20.3%) confirms hitters are expanding the zone far more against his new approach.
5. Chase Dollander — The Slider Addition
What changed: Dollander has introduced a true slider (18.2% usage, up from 0.6%), dropped his curveball usage by half, and leaned harder into his sinker while his fastball has ticked up to 99.0 mph.
| Pitch | 2025 Usage | 2026 Usage | Whiff% ‘25 | Whiff% ‘26 |
|---|---|---|---|---|
| 4-Seam | 47.3% | 33.8% | 20.9% | 28.6% |
| Sinker | 9.1% | 24.5% | 15.4% | 9.7% |
| Slider | 0.6% | 18.2% | – | 32.0% |
| Changeup | 7.3% | 14.9% | 21.3% | 36.4% |
| Curveball | 20.3% | 8.2% | 36.0% | 50.0% |
The slider has given Dollander a reliable mid-80s put-away pitch that he lacked in 2025 when he was primarily a heater/curveball guy. His K% jumped from 20.0% to 25.4%, and his BB% was cut nearly in half (10.9% → 5.6%) – a massive improvement in command. The changeup has also become a weapon (whiff% 21.3% → 36.4%), and his four-seam is sitting 99.0, up over a tick from last year. The more balanced arsenal has made him far less predictable.
6. Roki Sasaki — The Slider Reinvention
What changed: Sasaki completely reshaped his slider’s movement profile and doubled its usage. The pitch went from a sweeping horizontal breaker to a true vertical slider.
| Slider Metrics | 2025 | 2026 | Diff |
|---|---|---|---|
| Horiz. Break | +11.7” | +2.3” | -9.4” |
| Vert. Break | -2.3” | -1.5” | +0.8” |
| Velocity | 82.0 | 86.9 | +4.9 |
| Usage | 12.8% | 24.4% | +11.6% |
| Whiff% | 33.3% | 34.5% | +1.2% |
The 2025 slider swept glove-side nearly a foot. The 2026 version stays in the middle of the zone longer and breaks almost straight down, with nearly 5 mph of added velocity. It’s essentially a brand-new pitch. He’s also increased the splitter’s arm-side run (-2.0” → -4.1” HB) and reduced the four-seam usage from 49.7% to 46.6%. His K% has improved (16.7% → 20.0%), though walks remain an issue (13.2% → 20.0%). Sasaki is clearly still calibrating in his first full MLB season, but the slider reinvention gives him a true three-pitch mix rather than the fastball/splitter binary he relied on in 2025.
7. Cam Schlittler — The Sinker/Cutter Emergence
What changed: Schlittler was a fastball-dominant power arm in 2025 (54.3% four-seamers). In 2026, he’s dramatically diversified, cutting his heater usage nearly in half while tripling his sinker rate and boosting his cutter.
| Pitch | 2025 Usage | 2026 Usage | IVB ‘25 | IVB ‘26 |
|---|---|---|---|---|
| 4-Seam | 54.3% | 31.6% | 16.2” | 17.5” |
| Cutter | 19.5% | 29.3% | 5.4” | 11.8” |
| Sinker | 7.5% | 27.2% | 12.0” | 11.0” |
| Curveball | 14.5% | 9.5% | -12.4” | -8.9” |
The cutter’s movement profile has completely changed – it gained 6.4 inches of induced vertical break, making it play much more like a gyro-cutter than the traditional hard-breaking variety. Combined with the sinker’s arm-side run, Schlittler now attacks both sides of the plate instead of relying on the high four-seam/curve combo. The early results are excellent: K% jumped from 26.3% to 31.9% while BB% cratered from 8.8% to just 1.4%. His four-seam whiff rate also surged from 27.7% to 42.6% – fewer heaters are making each one more impactful.
8. Kodai Senga — The Velocity Spike
What changed: Senga’s four-seam has jumped from 94.7 mph to 96.4 mph – a 1.7 mph gain – while his overall arsenal distribution has stayed relatively similar, suggesting this is a health/mechanics change rather than a deliberate redesign.
| Pitch | 2025 Velo | 2026 Velo | 2025 Usage | 2026 Usage |
|---|---|---|---|---|
| 4-Seam | 94.7 | 96.4 | 30.5% | 36.1% |
| Forkball | 82.5 | 83.4 | 27.5% | 22.6% |
| Cutter | 89.6 | 89.5 | 19.6% | 21.0% |
| Sweeper | 79.6 | 79.8 | 5.9% | 13.1% |
After two years plagued by shoulder injuries, Senga appears healthier than at any point since coming to MLB. The added velocity has boosted his four-seam whiff rate (19.9% → 24.4%) and the cutter’s whiff rate jumped from 16.5% to 29.2%. He’s also showing the sweeper more frequently (5.9% → 13.1%), giving him a fifth look to complement the legendary forkball. K% is up from 23.1% to 29.7%, suggesting the velocity alone is changing the calculus for hitters who could catch up to the 94-95 heater but are overmatched at 96-97.
9. Jack Kochanowicz — The Changeup Weapon
What changed: Kochanowicz has more than doubled his changeup usage and tweaked its movement, turning a fringe offering into his primary swing-and-miss pitch.
| Pitch | 2025 Usage | 2026 Usage | Whiff% ‘25 | Whiff% ‘26 |
|---|---|---|---|---|
| Sinker | 45.6% | 36.0% | 13.9% | 17.5% |
| Changeup | 12.9% | 28.0% | 29.4% | 48.8% |
| 4-Seam | 17.6% | 18.6% | 25.9% | 8.3% |
| Slider | 14.5% | 17.1% | 26.9% | 46.2% |
His arm angle also shifted +7.3° (29.9° → 37.2°), which may explain the changeup’s improved movement – the horizontal break increased from -9.2” to -10.8” while the IVB dropped from 2.5” to 0.7”, giving it more drop-and-fade action. The changeup’s whiff rate nearly doubled from 29.4% to 48.8%, and his slider has seen a similar spike (26.9% → 46.2%). K% improved from 13.6% to 19.8%, though walks remain high (10.6% → 13.6%). The changeup turning into an elite put-away pitch gives him a realistic path to sticking in a rotation.
10. Slade Cecconi — The Cutter Revolution
What changed: Cecconi’s cutter usage went from a token 2.9% in 2025 to a primary offering at 22.7% in 2026, replacing his slider as the go-to breaking ball.
| Pitch | 2025 Usage | 2026 Usage | Whiff% ‘25 | Whiff% ‘26 |
|---|---|---|---|---|
| 4-Seam | 43.3% | 35.5% | 18.5% | 24.1% |
| Slider | 18.6% | – | 35.6% | – |
| Cutter | 2.9% | 22.7% | 16.7% | 17.1% |
| Curveball | 16.4% | 21.8% | 31.8% | 38.7% |
| Sweeper | 0.1% | 10.0% | – | 33.3% |
| Sinker | 10.8% | 9.7% | 4.5% | 0.0% |
Cecconi has essentially killed his traditional slider and replaced it with a cutter/sweeper combination – the cutter handles same-side hitters while the sweeper attacks opposite-side bats. The curveball’s whiff rate climbed from 31.8% to 38.7%, suggesting the cutter tunnels better off the heater than the old slider did. His four-seam whiff rate also jumped (18.5% → 24.1%). While K% is roughly flat (20.2% → 19.3%) and walks have ticked up (5.8% → 8.4%), the improved whiff numbers across the board suggest the results should catch up. The more diversified breaking ball portfolio gives him answers for different matchups that the slider alone couldn’t provide.
Key Themes Across These Changes
- The cutter wave continues: Kikuchi, Cecconi, Schlittler, and Hancock all added or dramatically increased cutter usage. The pitch bridges the gap between fastball and breaking ball, improving tunneling.
- Arm angle manipulation: Kikuchi (+13.9°), May (+9.3°), and Kochanowicz (+7.3°) all raised their arm slots, typically resulting in more ride on the fastball and better changeup/breaking ball deception.
- Sinker reduction: Soriano, Hancock, May, and Schlittler all cut sinker usage substantially, pivoting toward four-seam/elevated approaches that generate more whiffs.
- Mix diversification: Nearly every pitcher on this list went from 3-4 pitch mixes to 5-6 viable offerings, reflecting a league-wide trend toward unpredictability over stuff.