The cutter is a pitch with many names: the cut-fastball, the gyro ball, and the slutter. A cutter is considered a mix of the slider and four-seam fastball regarding vertical movement and speed.
Since 2019, there has been a steady league-wide increase in cutter usage. Baseball’s best pitchers, like Corbin Burnes, Shohei Ohtani, and Shane Bieber, have added a cutter in recent years. This increase in use, however, only scratches the surface of total cutter usage in the MLB today. The actual amount of pitchers throwing cutters is probably significantly higher than the 8.4% we saw in 2022. But why exactly are we seeing this increase in cutters?
Cutter or Cut Fastball?
One of the reasons for the rise in the popularity of the cutter is its versatility. A simple grip shift can turn a short, sliding cutter into a firmer, sharper cutter. This versatility, however, needs to be clarified on what precisely a cutter is. Where do we draw the line if a cutter can move like a slider? Why do we call the Houston Astros‘ Hunter Brown’s 94-mile-per-hour pitch a slider, not a cutter? And what’s the difference between a hard cutter and a four-seam fastball?
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In baseball, most cutters are thrown with gyro spin. This is when the ball spins like a bullet, causing vertical break and downward, horizontal movement. Sliders are often thrown with more gyro spin, causing the pitch to be slower and break down harder than a cutter. However, many pitchers blur the line with this pitch. Framber Valdez, for example, throws his cutter at 83 miles per hour with significant downward movement. These slower, slider-like cutters are called slutters, the mashing of the words cutter and slider.
Many of the cutters in the Major Leagues today fall into this gyro cutter or slutter definition.
The Rising Cutter
On paper, no pitch can rise. four-seam fastballs that seem to rise are an illusion caused by a mix of pitch release point, location, and spin efficiency. While these pitches do not rise on paper, in practice, four-seams with perceived rise are some of the best in the game. Generational pitchers like Justin Verlander, Jacob deGrom, and Gerrit Cole all throw fastballs with the illusion that they stay on the plane and rise after release. Just as some pitchers can throw 4-seam fastballs with rise, others can throw cutters with rise.
Rising cutters do not have gyro spin. Instead, they have a spin axis that slightly deviates from a four-seam fastball, sacrificing vertical movement for speed and a rising effect. Corbin Burnes is an example of a pitcher that relies heavily on his rising cutter.
Corbin Burnes
Burnes exemplifies why many pitchers shift to a cutter. Burnes threw his four-seam 58% of the time in 2019. With subpar vertical and horizontal movement, Burnes’s 4-seam was crushed to a .425 batting average against and a colossal .823 slugging. Burnes’ development of a cutter undoubtedly saved his career.
With the addition of his cutter in 2020, Burnes’ ERA dropped from 8.82 in 2019 down to 2.11. Recently, this cutter has been one of the best pitches in the MLB. Burnes’ cutter was the tenth-best pitch in the major leagues in 2022 and the best among cutters with a -21 run value.
While Burnes is off to a shaky start in 2023, his cutter movement is still 89% better than the average MLB cutter. If the cutter can save careers as it did with Burnes, why doesn’t every pitcher throw a cutter?
Pronation vs Supination
Pronation and supination occur in the wrist during the release of a baseball. Many pitchers have a natural tendency to either pronate or supinate. Naturally, pronating pitchers are more adept at throwing pitchers with arm-side runs such as sinkers and change-ups. Conversely, supinators turn the wrist outwards upon release, making them better at throwing cutters, sliders, and curveballs.
Many pitchers transitioning to a cutter are natural supinators, making the cutter a more comfortable pitch than the traditional four-seam fastball. While naturally pronating pitchers can develop a cutter, they are more likely slower gyro cutters, while naturally supinating pitchers can better throw firmer, rising cutters. Many of these natural supinators can even throw cutters off their four-seam fastball. Again, this brings us to the dilemma of how exactly we should be classifying the cutter.
The Cut Fastball
In interviews with Mariano Rivera about his cutter grip, Rivera often emphasizes how natural the pitch is for him. Kenley Jansen has also explained that his cutter was completely unintentional at first. Rivera and Jansen are most likely supinators because they can throw a cutter naturally. Supinated four-seam fastballs often have some cutter characteristics, mainly its glove side vertical movement. However, they have significantly sharper break and ride than the traditional cutter.
A big misconception about a cutter is that it has to move a lot to be effective. On the contrary, however, the cut fastball may be more impactful the less it moves. Mariano Rivera was dominant in his career, not because he threw hard or had tremendous movement, but because his cutter broke late enough and was little enough to miss the barrel’s sweet spot.
Many pitchers in the major leagues continue to throw this style of cutting fastball. Pete Fairbanks of the Tampa Bay Rays is a name undeservedly flies under the radar. Fairbanks throws his four-seam fastball with extreme natural supination. This results in a cutting fastball that holds its plane and breaks a couple of inches to his glove side. On top of the pitch’s deception, Fairbanks throws his cutting fastball at an average of 99 miles per hour.
Versatility
Ultimately, the expansion of the cutter can be credited to the pitch’s incredible versatility. Pitchers can add this pitch to their repertoire to pound the strike zone or get a swing-and-miss. Furthermore, the cutter is a platoon-neutral offering. Cutters that break away from right-handed batters are just as effective as cutters breaking into the hands of a lefty. As we learn more and more about supination and pronation, our understanding of pitchers that can throw an elite cutter will only grow. In the future, we can expect more and more pitchers to ditch their four-seam fastball in favor of a cutter, two-seam, or sinker.
Photo Credit: © Michael McLoone-USA TODAY Sports
Players mentioned:
Corbin Burnes, Shohei Ohtani, Shane Bieber, Hunter Brown, Framber Valdez, Justin Verlander, Gerrit Cole, Jacob deGrom, Mariano Rivera, Kenley Jansen, Pete Fairbanks
