Cut Fastball
Also known as: cutter, cut fastball
The cutter is a fastball with late glove-side movement — harder than a slider, smaller break than a slider — that jams or cuts away from hitters.
The cutter lives between the four-seamer and the slider in both velocity and movement. Thrown with a four-seam grip shifted slightly off-center (pressure on the middle finger), it cuts glove-side 2–4 inches late with minimal tilt. Because it looks like a fastball until the last 10–15 feet, it is extremely difficult to barrel. Left-handed pitchers use it to eat the hands of right-handed hitters; right-handers use it to run away from left-handers. Mariano Rivera's cutter — nearly his only pitch — is the most famous example in pro baseball history.
Start by simply shifting your four-seam grip one half-inch toward the middle finger and throwing at full effort. The small grip change will produce natural cut without any wrist manipulation.
Fine-tune cutter shape for specific matchups by varying middle-finger pressure: more pressure produces a tighter, smaller-break cutter ideal for eating right-handed hands. Lighter pressure with a touch more tilt produces a larger-breaking version that works away to left-handers.
Example
His cutter moved two inches glove-side at 91 mph, catching the end of the left-handed hitter's bat handle and producing a broken-bat groundout.
How it shows up on video
On camera, the cutter should be visually identical to the four-seamer until the final 15 feet of flight where the glove-side cut becomes visible. Common errors include a visible wrist turn before release that transforms the cutter into a slider, an uneven grip shift that produces varying amounts of cut between reps, and a release point that drifts glove-side compared to the four-seamer — creating an early visual divergence that alert hitters can learn to read.
Common mistakes
- Turning the wrist or forearm outward before release in an attempt to add cut, converting the pitch into a slower, loopier slider rather than a late-cutting fastball
- Uneven middle-finger pressure between reps, producing some pitches that cut as intended and others that behave like flat four-seamers with no movement
- Locating the cutter middle-middle where the small lateral movement does not reach the handle and the pitch sits over the fat part of the plate at fastball speed
- Over-gripping the off-center position so tightly that arm speed drops and the velocity gap between the four-seamer and cutter becomes readable by timing-conscious hitters
In SwingVantage Motion Lab
Motion Lab reads your arm path through the delivery from pose. It does not track the ball or compare pitch types, so it cannot show where your cutter and four-seamer split. Compare clips of both filmed from the same spot.
Related terms
- Four-Seam FastballThe four-seam fastball is the most common pitch in baseball — gripped across all four seams — and is usually the hardest, straightest pitch a pitcher throws.
- SliderThe slider is a breaking ball with lateral movement and some downward tilt, faster than a curveball and usually sharper in its late break.
- Horizontal BreakHorizontal break is the lateral movement a pitch generates from spin, measured in inches to the arm side (positive) or glove side (negative).
- Pitch TunnelingPitch tunneling is throwing different pitch types on the same early flight path so they separate late. The hitter can almost never tell them apart in time.
- Seam-Shifted Wake (SSW)Seam-shifted wake (SSW) is an airflow effect where off-center seams disturb the air unevenly. It causes movement that spin rate or axis alone can't predict.
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