No Velo, No Problem: Jhoan Durán’s Early Season Pitch-Mix Changes

[Cody Christie]

A lot has been made about Jhoan Durán’s velocity drop over the last two seasons. His early season performance points to him making strategic pitch-mix changes to counter his aging fastball.

Image courtesy of © Brad Rempel-Imagn Images

Jhoan Durán’s fastball has been his calling card throughout his professional career. His triple-digit heater lit up scoreboards when he was a minor-league starter, and that only increased after moving to the big-league bullpen. Casual fans love fastballs, and Durán was doing things that had never been done before by a Twins hurler. However, his performance has forced him to make pitch-mix changes. 

His early 2025 metrics suggest a deliberate evolution. Durán's four-seam fastball has dipped both in usage and velocity 

In response, he leaned heavily into his splitter, a pitch that has surged by nearly five percentage points and now challenges hitters with its late, tumbling action. Underlying these shifts is a subtle mechanical tweak: a drop in arm slot of roughly five degrees over the past two seasons. This tweak may explain both the change in the plane on his fastball and the slight tick off his radar gun. While no reliever can sustain 103–104 mph heat indefinitely, Durán’s adjustments are evidence of embracing a sustainable, multi‑pitch approach.

The Fastball’s Waning Spotlight
Durán’s four-seam fastball averaged an eye‑popping 101.8 mph in 2023, a number that vaulted him into elite company. However, Statcast data shows that the figure dropped to 100.5 mph in 2024, a career‑low, before settling around 100.1 mph through mid‑April of 2025. This isn’t an alarm bell so much as the natural arc of power arms. Few pitchers (outside Aroldis Chapman) sustain triple‑digit averages without occasional regression.

Concurrently, Durán’s reliance on the four-seamer has receded. He threw his heater on 40.7% of his pitches in 2024, a career‑low that reflected both health caution and strategic balance. He’s now deploying it in roughly the mid‑30s percent range early this season. Against modern MLB lineups hungry for velocity, the relative decrease underscores his willingness to diversify. Some lineups hunt for fastballs, but even his high velocity isn’t enough to blow away the league’s best bats. 

The Splinker’s Moment 
Durán’s split-finger/sinker hybrid (splinker) has blossomed into his primary put-away pitch, climbing nearly five percentage points from last season’s usage rate. Opponents must now respect late life as much as raw heat. It was the first “off-speed” pitch in MLB history to be clocked at over 100 mph, and he averaged 97.6 mph with his splinker in 2025. 

 

As a strikeout weapon, his splinker has made vast improvements this season. He has posted a 36.0 Whiff% and a 30.0 Put Away%, respectively, whereas last season, both totals were in the low 20s. Batters have been held to a .091 BA and a .091 SLG when facing his best pitch, as he has only allowed one hit with it in 13 plate appearances. Its sinking action has created a ground‑ball complement (-25 launch angle) to his vertical power pitches. This duality makes Durán a more complete reliever.

The Mechanics: Arm Slot Adjustment 
Statcast’s arm angle data reveals Durán has lowered his arm slot from the upper 30s (2023 season) toward the mid‑30s over the past two seasons. Where he once operated around a 39° release, he’s now closer to 33°, a subtle shift that alters both spin orientation and perceived plane.

A slightly flatter arm slot reduces vertical ride on his four‑seam fastball in favor of more lateral run, contributing to the sense of “cut” on what remains a high‑velocity pitch. Conversely, the splitter benefits from the change, as the grip and release angle further accentuate its downward break, enhancing its effectiveness even as its velocity holds in the high 90s.

A Sustainable Blueprint 
Baseball’s aging curves show that most pitchers peak in fastball velocity in their early 20s, then decline by roughly 1 mph by age 26 and beyond. Some legendary flamethrowers that once regularly touched 100 mph have seen the mid‑90s become the norm later in their careers. Durán’s current marks are not a deficiency but a recalibration. 

Durán’s 2025 season will be defined by a pitcher adapting in real-time to the realities of arm health, aging curves, and hitter evolution. By leaning into his splinker and refining his arm slot, Durán is following a tried‑and‑true path: when heat is harder to sustain, complementary weapons and refined mechanics become the keys to longevity. If the mantra is "No Velo, No Problem," then Durán’s early returns suggest his new toolkit will keep him humming through the summer and into October.

Can Durán be successful with his new pitch mix? Leave a comment and start the discussion.

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[gil4]

That splinker/sweeper overlay is crazy.
 

[bean5302]

Duran through first 9 appearances
2022 = 100.0
2023 = 101.4 <-- outlier, not the norm
2024 = 100.6
2025 = 100.1

[DamianKinzler]

Relax😂 he’s still throwing up to 103. I witnessed it already this season 

[DocBauer]

After 9 appearances do we have any sort of accurate read on Duran? He wasn't god-like in 2024 but he was still good.

His power curve has actually been probably his best pitch previously. His splinker maybe his 2nd best pitch at times. The velocity of his FB has dropped from super human to beyond human. I've said many times, maybe taking a little off his other pitches might make a difference to confuse batters IF his velocity is down. If his FB is only 99-100, then take 2-3 mph off the other offerings.

But then I saw him blow a 102MPH fastball for strike 3 to close a win a couple days ago!

Duran is only 27yo. But the body isn't designed, generally speaking, to throw like that long term. Adjustments need to be made. Sequencing and maybe a 4th pitch, even if it's a "show me" offering can make a difference. But while i 100% agree with bullpen usage being based on best arms for the best usage in critical situations,  MAYBE Duran just has the old school mindset that he's going to "close the door"! And maybe he doesn't. But IF HE DOES he is still important. 

[LambchoP]

Are we really worried about Duran's velo when he's been throwing 101-102? His new sweeper looks like a great new pitch too. Duran looks just fine this year. I'm more worried about the start Jax has gotten off to.