Archive file · Specimen No. 06

Splinker

It leaves the hand like the fastball, then sinks and runs like a splitter.

Open this like an archive drawer: grip first, source attached, shape in words, no invented spin or movement numbers. The file exists so the hold can keep moving forward.

Shape read

Holds flat · arm-side run

It holds the four-seam line for most of the way, then drops late and runs to the throwing-arm side — a sudden, heavy dive off a fastball look. Down and arm-side, arriving where the four-seam never does.

ShapeOfficial data

A light two-seam split: the index and middle fingers split wide across a two-seam orientation with the ball held shallow, not wedged deep like a traditional splitter. Skenes adds index-finger pressure for the arm-side tail.

FastballThe hybridMagnus, arm-side + sink

GripReputable analysis

Open the grip file All pitches

Archive Drawer / Grip Lab

The artifact in the hand

Lead with the hand. The fingers on the ball below are the sourced contacts, solved onto the seam. Drag the ball, or use the view buttons.

Reputable analysisMLB.com, Explaining Skenes' expanding arsenal (Mike Petriello)

View

Hand

Keyboard: arrows switch views · F flips the hand · H lifts it

01Split your index and middle fingers wide across a two-seam orientation.
02Hold the ball shallow between them, not wedged deep like a splitter.
03Add a little extra pressure with your index finger to pull the arm-side tail.
04Throw it with fastball arm speed; the light, low-spin split gives you the late dive.

What it should feel like

Throw it like the fastball. The light split and a little index pressure add the dive.

Grip geometry is schematic. Skenes shows a clearly split grip on a two-seam orientation; the index-finger-pressure detail is reporter paraphrase, not a verbatim quote.

Ball depth

Out in the fingers

Spacing

Wide spacing

The sourced grip, in full

Reputable analysisMLB.com, Explaining Skenes' expanding arsenal (Mike Petriello)/ 2025

Grip mechanics are reporter paraphrase (MLB.com and Yahoo Sports on Skenes demonstrating it), not the pitcher's verbatim words.

Skenes has said the grip itself did not change when the modern, sharper version emerged; his release and the feel at release changed, which he stumbled onto on one random throw and then repeated.

Reputable analysisFOX Sports, Paul Skenes and his splinker at the All-Star Game/ 2024

Paraphrased from Skenes' FOX Sports account; his direct quote is in the chapter's voice.

Duran reached his version by widening a sinker grip; the pitch surfaced by accident in a 2018 bullpen, then he kept it. Both arms hold it to look like the four-seam out of the hand.

Reputable analysisMLB.com, Meet the 'splinker' pitch (Jhoan Duran, Do-Hyoung Park)/ 2022

From MLB.com's feature on Duran, who first popularized the pitch.

Release Room

Translate the hold into a release

Grip shape only matters if the release makes sense. Read pressure, thumb support, and ball depth before you read the pitch shape.

Hold

A light two-seam split, the ball held shallow, not wedged deep between the fingers.

Pressure

Adds the arm-side tail with extra pressure

Leave

Fastball arm and full intent; the light split and index pressure add the sink and tail.

Thrown with fastball arm speed and full intent. The light, low-spin split lets the ball drop and run to the arm side, and because it leaves the hand on nearly the same path as the four-seam, hitters cannot separate the riding fastball from the diving hybrid until it falls.

Reputable analysisMLB.com, A splinker? Skenes' hybrid pitch (debut, Alex Stumpf)/ 2024

Paraphrased from MLB.com's coverage of Skenes' debut splinker.

Movement

A fastball look off the same arm, then a late dive and arm-side run.

The read is shape, not a gauge. The spin words explain why it moves that way, and every prose claim still carries its source.

Shape

Holds flat · arm-side run

Official dataMLB.com, A splinker? Skenes' hybrid pitch (debut, Alex Stumpf)/ 2024

Spin words

A low-spin, sinker-like axis with arm-side tilt, but the flight path stays close to the four-seam's out of the hand, so the two look alike before the splinker dives.

Reputable analysisMLB.com, Skenes' newest pitch is his confidence pitch (Alex Stumpf)/ 2024

Craft read

It tunnels off the four-seam, leaving the hand on nearly the same path at fastball speed. Then the light split lets it dive down and toward the throwing arm, so the hitter has to guess which fastball is coming.

The one teaching sentence

It is a second fastball shape: fastball arm speed off the same slot and release as the four-seam, then a late dive and arm-side run the four-seam never makes. The hitter has to choose between the riding pitch and the diving one out of the same hand.

Reputable analysisMLB.com, Skenes' newest pitch is his confidence pitch (Alex Stumpf)/ 2024

Master Files

Three ways the same pitch wins

The few arms throwing it: the one who popularized it, the one who made it famous, and the closers chasing it. The visual is our own seam schematic. What sets each version apart is in the read, not a gauge.

Paul Skenes

Made the pitch famous. Discovered it by accident playing catch after the 2023 College World Series, then turned it into one of the most valuable pitches in baseball.

The definitive modern splinker: a fastball look that holds the four-seam line, then dives arm-side and down so late hitters keep waving over it. It plays like a second fastball with a trapdoor.

Official dataMLB.com, Explaining Skenes' expanding arsenal (Mike Petriello)/ 2025

Jhoan Duran

The arm who first popularized the splinker, discovering it in a 2018 bullpen after widening a sinker grip. The power version of the pitch.

The power version: splitter-grade arm-side dive carried with fastball intent, so the dive lands without the usual soft-pitch tell.

Reputable analysisFanGraphs, Jhoan Duran and the One True Split-Finger Fastball/ 2025

Mason Miller

Added the splinker to a triple-digit fastball and a wipeout slider, unveiling it in a May 2024 game with extra horizontal ride.

Bolted onto an elite power arsenal — his version leans hard to extra arm-side run, a third look off the same upper-tier heat and the wipeout slider.

Official dataMLB.com, Mason Miller adds a splinker/ 2024

The colophon

Every claim, sourced

Nothing here is marked right or wrong. It is marked by where it came from and how confident the source is. A broken citation throws at build, so a dead source never reaches you.

Official dataPitcher's own wordsCoach-observedReputable analysisSecondhand, attributed

108 double stitches, 216 individual · seam-informed schematic · as of the dates above

The arm who owned it

C-07 · 2024-present

Paul Skenes

SplinkerOpen the file →

Others in the fastball

Four-seam fastball Two-seam fastball Cutter

Tier 03 / Field Notes

Field notes from the bullpen.

Every pitcher fiddles. A thumb creeps lower, a seam catches more leather, a cue from a coach suddenly makes the pitch move. Pitch Atlas files those experiments as specimens with context, so the small discoveries stop disappearing into group chats and comment sections.

How notes rank

Evidence and context, never who shouts loudest.

There is no single correct way to throw a pitch, but there are better and worse claims. A funny line should never outrank a tested grip. So notes do not rise on raw votes. They rise on weighted signals - provenance and adoption first.

35%
Provenance
Source tier and evidence. A coach-observed note with a link outranks an unverified hunch with none.
20%
Adoption
How many other pitchers independently tried the same tweak. Real replication, not passive clicks.
20%
Usefulness
Marked useful, measured against views so a small loud crowd cannot stuff the rank.
15%
Context match
How close a note is to your level, slot, and pace context. Computed in your session, never stored.
10%
Community confidence
Considered practice: a real sample size behind the claim, not one good bullpen.

The vocabulary

Field Note: One pitcher's report on a grip variant.
Variant: A specific, named change from the canonical grip.
Tried This: A second contributor replicating the tweak.
Coach Note: A coach reporting on an arm they work with.
Source Challenge: A standing request for the evidence behind a claim.
Provenance: The source tier and evidence that set a note’s rank.
Adoption: How many others independently tried it.
Needs Evidence: A note flagged for missing support, kept visible.

Your bullpen card

0 pts

Filing as an unclaimed contributor · anonymous.

Log a field note

Throw the splinker with a wrinkle of your own? Add it. Label where it comes from: your own report, a coach, or a hunch. Keep it to grip and technique only. No medical, injury, workload, or youth-training prescriptions. Sourced, not corrected.

Field notes for the splinker

Keeping the bullpen honest

Field Notes are live for grip and technique only. No medical, injury, workload, or youth-training prescriptions. Every note carries a source and confidence label, and contributors can report problems. No abuse, no personal attacks, no off-topic spam, nothing aimed at minors. New field notes stay private until review. See a problem with a public note? Use Report on it; a note flagged by enough people is hidden automatically until it is checked.

Every community variant carries the same source and confidence labels as the records above. Nothing appears here unsourced, and no count is shown until it is real.