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How to Throw a Curveball

Welcome to the world of baseball pitches, where the curveball reigns as a crafty sovereign on the mound.

In baseball’s storied history, various types of pitches have bamboozled batters, from fastballs to sliders, changeups to knuckleballs.

how to throw a curveball featured image

Yet, the curveball, a type of pitch in baseball thrown with a characteristic grip and hand movement that imparts forward spin to the ball causing it to dive (i.e. “break”) in a downward path as it approaches the plate, has carved a niche as a captivating spectacle with its deceiving arc and sudden drop.

Table of Contents

The Curveball’s Heritage

Tracing its roots back to the late 19th century, the curveball emerged as a revolutionary weapon in a pitcher’s arsenal.

The origin of the word “curveball” in baseball vernacular is intrinsically tied to the physical description of the pitch itself. The term likely evolved from the observable “curve” or arc that the ball makes in flight when thrown with a certain spin. This spin causes the ball to move laterally and downward, deviating from a straight path to the plate, hence the term “curveball.”

It was first attributed to pitchers like Candy Cummings, who is credited with being one of the original inventors of the curveball.

The term encapsulates both the action of the pitch and the surprise it represents—a pitch that quite literally “throws a curve,” defying the expected straight trajectory of a typical throw.

Since then, this breaking ball known as the “curveball” has revolutionized modern baseball and even transcended baseball, becoming a metaphor used widely to describe any unexpected twist or challenge in various aspects of life.

Over the years, the curveball has been both an art and a science, with pitchers such as Sandy Koufax, Bert Blyleven, and in more recent times, Clayton Kershaw (with his signature 12-6 curveball), demonstrating its effectiveness at the highest levels.

Flight of the Curveball

The flight of a curveball is one of baseball’s most intriguing phenomena, a ballet of physics that defies the batter’s expectations. Technically, the curveball’s enigmatic movement is the result of three key physical principles: spin, speed, and the resulting Magnus effect.

how to throw a curveball - magnus effect

When a pitcher releases a curveball with the correct grip, their fingers apply forward spin to the ball at a high rotation rate. This spin is crucial—it’s what gives the curveball its name and its distinctive flight pattern.

The top of the ball moves with the direction of the pitch, while the bottom of the ball moves against it, creating an uneven pressure distribution around the ball due to air resistance. The side of the ball spinning against the pitch direction encounters more air resistance, which slows down the air on that side.

Meanwhile, the side spinning with the pitch direction speeds the air up. This differential in air pressure results in lower pressure on the top and higher pressure on the bottom, pushing the ball downward—a force known as the Magnus effect.

The Magnus effect, named after physicist Heinrich Gustav Magnus, who described it in 1852, is what causes the curveball to “break.” Break refers to the point where the ball significantly changes trajectory from its initial path.

The amount of break, both in terms of angle and depth, depends on several factors: the rotation rate (spin), the speed of the pitch, and the grip. A “tight” spin, or high rotation rate, usually results in a sharper break, as there’s more uneven pressure applied to the ball.

how to throw a curveball - stich pattern from batter's perspective

Pitchers often talk about a “12-6 curveball,” which describes the ball’s movement in terms of the face of a clock: dropping from 12 o’clock to 6 o’clock. This pitch has little to no horizontal movement and is considered the ideal or “true” curveball.

However, most curveballs also have some horizontal movement depending on the pitcher’s arm angle and grip variation, leading to different types of curves, such as the “slurve,” which blends elements of a slider and a curveball.

Advanced analysis tools like high-speed cameras and pitch-tracking technology have allowed scientists and coaches to study the curveball in great detail, measuring its spin rate, axis of rotation, and the exact trajectory.

Understanding the minutiae of these mechanics helps pitchers refine their technique to maximize the effectiveness of their curveball, making it one of baseball’s most complex and fascinating pitches.

Why Pitchers Love Curveballs

Pitchers are enamored with the curveball for its strategic value in the art of deception and its ability to disrupt a batter’s rhythm and confidence.

The key to a successful pitching strategy is variation, and having a curveball in your repertoire—whether it’s the classic curveball or a specialized 12-6 curveball—provides that essential unpredictability.

When a pitcher can throw a curveball with the same arm action as a fastball but with the distinct curveball grip, it becomes exceedingly difficult for batters to differentiate between the pitches until it’s too late.


A curveball, especially one with a sharp break like a 12-6, can appear to be in the strike zone until it dives down, potentially resulting in a swing and a miss or weak contact. This element of surprise is what is meant by “throwing a curveball,” both in baseball and in common vernacular.

Additionally, the curveball’s slower speed compared to a fastball gives the pitcher a tactical advantage. A well-timed curve can throw off a batter’s timing after they’ve geared up for a faster pitch.

The most effective curveballs will start breaking at the height of the arc of the ball flight, and continue to break more and more rapidly as they approach and cross through the strike zone. When thrown correctly, it could have a break from seven to as much as 20 inches in comparison to the same pitcher’s fastball.

“Hanging” curveball is when the ball does not drop off, which makes it easier for a batter to hit the ball out of the park.

The Batter’s Perspective

From the batter’s box, the curveball is a pitch that demands split-second adjustments and a solid mental game. When a pitcher releases a curveball, the batter initially sees it as a fastball. The pitcher’s arm speed and release point give no immediate indication of the impending break. It’s this initial deception that lays the groundwork for the curveball’s effectiveness.

As the curveball travels its flight towards home plate, the batter must quickly discern the spin of the ball. A curveball spins forward, toward the batter, distinguishing itself from the backspin of a fastball. The hitter’s ability to pick up on this subtle cue—a skill honed over countless pitches—can mean the difference between connecting with the ball or being completely fooled by it.

Once identified, the curveball presents a new challenge. As it arcs, a curveball can “freeze” batters, causing them to hesitate as they try to track its break. When the ball finally dives—often in a dramatic 12-6 motion—the batter must attempt to adjust their swing path to meet it. This is further complicated by the fact that not all curveballs are created equal. Some may have a sweeping movement, while others, like the famed Kershaw’s curveball, display a pronounced vertical drop.

The speed difference between a fastball and a curveball also poses a significant challenge. After gearing up for a fastball, the batter must slow their swing to match the curveball’s velocity. This is where timing is crucial, and why curveballs can be so effective as an off-speed pitch. The batter’s muscle memory, trained for the fastball’s pace, must be overridden in a moment’s notice to adapt to the slower speed of the curveball.

In youth baseball, where the curveball is less common, the effect is even more pronounced. Young hitters are often advised on how to hit a curveball, with coaches emphasizing the importance of patience and waiting on the ball. However, because young players have less experience with the pitch, a well-thrown curveball can be particularly effective at those levels.

The curveball’s impact extends beyond a single pitch. Even if a batter successfully hits a curveball, the knowledge that the pitcher can throw it adds a layer of psychological warfare to each at-bat. The batter must constantly anticipate the possibility of the curve, which can lead to overthinking and hesitation, affecting their approach to other pitches as well.

For batters, curveballs present a unique challenge. The movement can be so sudden and severe that it leads to swings and misses, or at the very least, poor contact. A curveball in baseball can look like a high fastball out of the pitcher’s hand, only to dive out of the strike zone at the last moment.

How to Throw the Perfect Curveball

In the early days of baseball, the “old method” of throwing a curveball was less refined and more instinctual, with pitchers often developing their own unique styles through trial and error. The focus was primarily on achieving the most dramatic movement along with deception, with less regard for the long-term health of the pitcher’s arm.

Today, with better understanding and technology, methods emphasize efficiency and safety alongside effectiveness.

Old Grip vs. Modern Grip

The grip in the old method was often a deep one, where pitchers would clutch the ball firmly in their palm, using intense pressure from their fingers to generate spin.

This “choke” grip allowed for a significant amount of spin but required considerable force, which could lead to higher stress on the fingers, wrist, and forearm.

The ball was held tightly against the hand, and the seams were used more as a guide than as a means to facilitate spin. This approach tended to increased strain on the arm, as the grip was excessively tight.

The modern curveball grip is more akin to holding a cup or drinking glass.

The pitcher places their middle finger along one of the ball’s long seams, and positions the thumb on the opposite side of the ball, just behind the seam.

Viewed from above, the pitcher’s hand should form a ‘C’ shape, with the ball’s horseshoe seam curving inward towards the palm, following the thumb’s contour.

The index finger is placed next to the middle finger for support, while the ring and little fingers are tucked into the palm. The ring finger’s knuckle may lightly touch the ball’s surface.

Some pitchers prefer to extend these two fingers away from the ball, keeping them out of the way during the pitch. The grips and motions for throwing a curveball and a slider are very similar, with only slight variations that affect the ball’s movement.

The modern gripping method reduces the tension in the hand and arm, facilitating a high spin rate while minimizing the undue strain.

Old Pitching Motion vs. Modern Pitching Motion

Historically, old way of throwing curveballs would require a pitcher to use a pronounced wrist snap combined with a vigorous forearm motion to throw the curveball to generate a motion thought to increase the ball’s spin.

However, this put tremendous stress on the elbow and shoulder. The entire arm, especially the elbow joint, was subjected to a lot of torque and stress due to this exaggerated snapping motion.

The focus of old pitching motion was to create pitch movement at the expense of less consistent delivery and greater physical exertion.

In contrast to the old, more strenuous methods, the new approach to the pitching motion for a curveball is more aligned with a pitcher’s overall mechanics, emphasizing fluidity, arm health, and sustainability.

  • Consistent Arm Action – The new method stresses the importance of a consistent arm action across all pitches. This means that the motion used to throw a curveball should closely mimic the motion of a fastball. By maintaining a similar arm speed and path, pitchers can disguise their pitches better, making it harder for batters to differentiate between a fastball and a curveball until it’s too late.
  • Minimizing Wrist Snap – Rather than the aggressive wrist snap characteristic of the old method, the modern pitching motion for a curveball uses a more controlled and less pronounced wrist action. The wrist is still involved in generating spin, but it’s done in a way that is more of a natural extension of the arm’s movement rather than an isolated, forceful snap. This subtler wrist action is less taxing on the ligaments and tendons, mitigating the risk of injuries such as sprains or tendonitis.
  • Maximizing Spin with Finger Pressure – Instead of relying on the wrist to do all the work, today’s pitchers are taught to use their fingers to maximize the spin on the curveball. The pressure applied by the middle finger at the point of release is crucial for imparting the necessary topspin on the ball. This technique allows for a tight, efficient spin without the excessive torque that used to be applied to the arm and elbow.
  • Efficient Kinetic Chain Usage – Modern pitching coaches emphasize the importance of using the entire body in a coordinated effort, known as the kinetic chain, to produce the pitch’s power and spin. This starts with the pitcher’s legs and hips, which generate the initial force that is then transferred through the torso, shoulder, and down the arm. By engaging the body in this manner, the arm is not left to do all the work, and the stress on the elbow and shoulder is significantly reduced.

Proper Release Point

Early curveball practitioners often experimented with various release points, trying to find the one that would produce the most dramatic break. This could lead to inconsistency and arm problems, as pitchers contorted their mechanics to achieve the desired effect.

Today, the emphasis now on a consistent release point, similar to that of a fastball. The key is to release the curveball out in front of the body, with the fingers pulling down on the seam to create topspin. The pitcher’s follow-through is critical, with a focus on finishing the pitch with the arm moving downward in a natural, comfortable motion.

By combining these modern methods of grip, motion, and release, pitchers can develop a curveball that is not only effective but also sustainable over a long career. This evolution reflects a broader shift in baseball towards player health and longevity, ensuring that the magic of the curveball continues to delight fans for generations to come.

Follow-Through and Deceleration

An often-overlooked aspect of the pitching motion is the follow-through. In the new method, the follow-through is given as much attention as the wind-up and release.

After the ball is released, pitchers are encouraged to let their arm continue its natural motion downward and across the body. This helps to decelerate the arm in a controlled manner, which is essential for reducing stress on the pitching arm and avoiding injury.

Repetition and Muscle Memory

The modern curveball pitching motion is also about repetition and muscle memory.

By practicing the motion repeatedly, pitchers can develop a feel for the pitch that allows them to throw it with minimal conscious effort. This consistency is key for maintaining proper mechanics throughout a game and a season

Controversies in Youth Baseball

For young pitchers, understanding how to throw a curveball—and more importantly, when to throw a curveball—can be a game-changer. The appropriate age for young pitchers to begin throwing curveballs has been a topic of debate and research within the baseball and sports medicine communities.

According to various studies and position statements by organizations such as the American Sports Medicine Institute (ASMI) and Little League Baseball, it is generally recommended that pitchers wait until they are around 14 to 16 years old before incorporating curveballs into their repertoire.

The concern with throwing curveballs at a younger age centers on the physical development of young athletes. Their bones, muscles, and connective tissues are still maturing, and the repetitive stress of pitching—particularly the torque required for curveballs—can increase the risk of arm injuries.

The growth plates in a young athlete’s elbows and shoulders are especially susceptible to injury from the twisting motions involved in throwing breaking pitches.

The ASMI has stated that there is no evidence to suggest that curveballs before the age of 14 are more dangerous than other pitches, but they emphasize that proper mechanics, pitch counts, and adequate rest are crucial regardless of the type of pitch thrown.

It’s also essential to ensure that young pitchers have developed sufficient physical strength and pitching technique before attempting advanced pitches like curveballs.

While there isn’t a universally agreed-upon “safe” age, the cautious and widely accepted recommendation leans toward the early teenage years (13-15 years old). This conservative approach aims to balance the development of a young pitcher’s skills with the imperative of preventing overuse injuries.

** Remember that Little league curveball rules often recommend caution or restrict the pitch entirely to protect young arms.


Learning the importance of mastering the proper curveball grip and throwing motion cannot be overstated, especially when it comes to reducing the risk of injury.

A well-executed curveball starts with a nuanced grip that avoids undue strain on the arm, complemented by a fluid pitching motion that respects the body’s natural mechanics.

Emphasizing these correct techniques is not just about enhancing performance; it’s about safeguarding the health and longevity of pitchers. The repetitive nature of pitching, particularly with complex pitches like curveballs, can pose significant risks to a pitcher’s arm, making proper form crucial. Integrating these best practices into a pitcher’s routine from an early age helps establish a foundation for a sustainable and injury-free career.

According to the consensus in the sports medicine community, the appropriate age to start throwing curveballs, leans towards caution. Waiting until the early teenage years, around 14 to 16, allows young pitchers to develop physically and acquire the fundamental skills and strength necessary for more advanced pitches. This approach balances the excitement and challenge of learning a curveball with the paramount importance of health and safety.

By emphasizing proper grip, motion, and age considerations, pitchers can dazzle fans and outsmart batters but also enjoy a long, healthy journey in the sport they love.

Frequently Asked Questions

  • When should I throw a curveball?
    • Since most batters prefer an inside pitch instead of outside pitch, right-handed pitcher usually throws to right-handed batter and left-handed pitcher to left-handed batter.
  • Is it safe for my child to learn a curveball at a young age?
    • The consensus among sports medicine experts is to wait until a child is at least 14 to 16 years old before introducing the curveball. This recommendation is based on the physical development of young athletes, as their bones and ligaments are still maturing. Introducing complex pitches like the curveball at a younger age can increase the risk of arm injuries.
  • How can I ensure my child is using the correct technique when throwing a curveball?
    • Proper technique is crucial to reduce the risk of injury. Ensure your child learns from a qualified coach who can teach the correct grip and pitching motion. Emphasizing a smooth, natural arm action and avoiding a forceful wrist snap are key. It’s also beneficial to periodically have your child’s technique evaluated by a pitching coach or sports specialist.
  • What signs of injury should I look out for in my young pitcher?
    • Be vigilant for signs such as persistent arm or elbow pain, decreased pitching accuracy or speed, visible swelling, or changes in arm motion. Any of these symptoms may indicate an injury and should be evaluated by a healthcare professional. Regular rest and monitoring pitch counts are important to prevent overuse injuries.
  • Are there specific conditioning exercises my child should do to prepare for pitching a curveball?
    • Yes, focusing on overall body strength, flexibility, and core stability can help prepare a young pitcher. Exercises that strengthen the shoulder, forearm, and wrist, as well as core stability workouts, are particularly beneficial. It’s also important to ensure that your child is doing proper warm-up and cool-down exercises during practice sessions.
  • How many curveballs should my child throw in a game or practice session?
    • Limiting the number of curveballs thrown per game and practice is crucial to reduce wear and tear on the arm. Guidelines vary, but a general rule is that young pitchers should not throw curveballs more than 20-30% of their total pitches. It’s also important to adhere to overall pitch count limits set by youth baseball organizations to prevent overuse injuries.