What is a Cutter? Definition and Examples
A cutter is a fastball variant — typically 2-5 mph slower than a four-seamer — that breaks late toward the pitcher's glove side, splitting the difference between a fastball and a slider.
What is a cutter?
A cutter, or cut fastball, is a fastball variant that breaks late toward the pitcher's glove side — a few inches, sharply, right at the front of the plate. For a right-handed pitcher, it runs in on the hands of left-handed hitters and away from right-handers. Velocity sits 2 to 5 mph below the pitcher's four-seamer, usually in the 86 to 94 mph range, though the hardest cutters in MLB push 100 mph. Think of it as the pitch that splits the difference between a four-seam fastball and a slider: fastball-fast out of the hand, slider-shaped at the plate.
How a cutter is thrown
The grip sits slightly off-center compared to a four-seam fastball. The middle finger rides the outer edge of the horseshoe seam, with a subtle wrist tilt at release. Instead of pure backspin, the cutter's spin axis tilts toward gyro, producing less "ride" (induced vertical break) than a four-seamer and 2 to 6 inches of glove-side horizontal break. On a Statcast pitch-shape chart, cutters live in the valley between four-seam fastballs and sliders. Trackman and Statcast classify them primarily by velocity relative to the pitcher's heater and by spin axis — which is why cutter versus slider classification can flip depending on the algorithm.
Worked example: Rivera, Burnes, and Clase
Mariano Rivera built a Hall of Fame career on one pitch. His cutter sat 91-94 mph with enough late movement to saw bats off left-handed hitters — he threw it over 80% of the time for more than a decade and hitters still couldn't square it. More recently, Corbin Burnes rode his cutter to the 2021 NL Cy Young. In 2023 he threw it about 49% of the time at 95.3 mph with 2.2 inches of horizontal break and 10.5 inches of induced vertical break, using it as effectively a primary fastball. Emmanuel Clase throws the hardest cutter in MLB history, averaging 99-101 mph with over six inches of cut — a pitch that by measurement alone shouldn't exist. On the soft end, Kyle Hendricks' 86 mph cutter shows the pitch works at any velocity band if the movement plays off the rest of the arsenal.
Why the cutter matters
The cutter is the sport's most elite bat-breaker. Because it arrives fastball-fast but moves late, hitters commit to it as a fastball and then get jammed on the hands — producing broken bats, weak pop-ups, and ground balls rather than big swings and misses. It's especially deadly against opposite-handed hitters, which is why it's often a starter's third pitch added specifically to neutralize the platoon split. Pitchers who develop a usable cutter frequently break out without any change in raw velocity — Burnes in 2021 is the textbook case. Teams target it as a development pitch because it tunnels well with both four-seamers and sliders.
Limitations and common misconceptions
If velocity drops below roughly 87 mph and horizontal break exceeds 6 inches, pitch-classification systems often reclassify the pitch as a slider — the "slutter" label exists exactly because the boundary is fuzzy. A cutter is not a two-seamer or a sinker; those break to the arm side, the opposite direction. It's also not a splitter or a changeup — those kill velocity much more aggressively and work on a vertical plane. And a cutter with no meaningful velocity gap from the pitcher's four-seamer usually just plays like a dead-straight fastball.
Related terms
In Legends Deck
Legends Deck models pitch arsenals at the individual pitch level, so a cutter is a distinct card attribute with its own velocity, horizontal break, and vertical break. When the sim rolls contact quality, a high-grade cutter (think Burnes or Clase) biases the outcome toward weak contact and broken bats — ground balls and soft fly balls rather than barrels. That's why pitcher cards with an elite cutter tend to out-perform their strikeout rates in the sim's run-prevention numbers, the same way Rivera out-pitched his raw K% for a generation.