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. This means the small grip change will produce natural cut without any wrist manipulation.
Fine-tune cutter shape for specific matchups by varying middle-finger pressure. This means 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. A release point that drifts glove-side compared to the four-seamer. This means 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
SwingVantage overlays release point coordinates and wrist orientation across cutter and four-seam reps to verify that both pitches depart from the same spatial window. A grip-induced wrist turn is detectable in the forearm rotation data before the pitch is released. This gives pitchers early feedback on whether their cutter will arrive with the intended late-breaking profile.
Related terms
- Four-Seam FastballThe four-seam fastball is the most common pitch in baseball — gripped across all four seams — and is typically 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 typically 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 the strategy of throwing different pitch types that share the same flight path early before diverging late. This means making it nearly impossible for the hitter to distinguish them in time.
- Seam-Shifted Wake (SSW)Seam-Shifted Wake is an aerodynamic effect where an off-center seam orientation disrupts airflow asymmetrically. This produces movement that cannot be predicted from spin rate or axis alone.
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